QUOTE (David B. Benson+May 13 2007, 11:16 PM)
We conclude that after T/2 = 0.131 (or so) seconds, the weakest column member, the one in fire and impact affected zone, not only has a load about twice what it was designed to handle on the top, but it has the lower portion of the column expanding upwards. It buckles!
Hello David B. Benson,
This is quite interesting.
Is there some way (not vastly more complicatied) to solve this problem analytically for a column that has a linearly increasing density from top to bottom? Or is your calculation establishing a useful lower bound on such a non-uniform density variation on your problem?
Hello David B. Benson,
This is quite interesting.
Is there some way (not vastly more complicatied) to solve this problem analytically for a column that has a linearly increasing density from top to bottom? Or is your calculation establishing a useful lower bound on such a non-uniform density variation on your problem?
lozenge124
Here is an example of what passes for "scholarship" on this site
in "Estimates for time to collapse of WTC1" it states...
"In [10]it states: Virtually all the concrete (an estimated 100,000
tons in each tower) on every floor was pulverized into a very fine dust, a phenomenon that requires enormous
energy and could not be caused by gravity alone; workers can't even find concrete.""
As if this was a scientifically proven fact. It's reference is another paper on this "scholarly" site...
Why Did the Trade Center Skyscrapers Collapse?
by Morgan Reynolds
"Virtually all the concrete (an estimated 100,000 tons in each tower) on every floor was pulverized into a very fine dust, a phenomenon that requires enormous energy and could not be caused by gravity alone ("…workers can’t even find concrete. ‘It’s all dust,’ [the official] said")."
Which references this ABC News site...
http://911research.wtc7.net/cache/disinfo/...osurvivors.html
And a report on survivors dated Sept 16, 2001 in which is the following paragraph...
"Rescue workers have been searching around the clock for survivors of the twin towers disaster. But the efforts remain painstakingly difficult and tumultuous. One official said that workers can't even find concrete. "It's all dust," he said."
An unattributed quote in a news report five days after the event(and weeks before they found the concrete rubble(not pulverized) in the basements) becomes a scientific fact because it is referenced in another "scholar's" paper??? Who is the "one official" and did he know that the concrete would be found weeks later in the basement??? Had he conducted a scientific investigation of the whereabouts of the concrete, or was he just expressing his frustration about being unable to find any survivors???
This is CRAP "science" piled on other CRAP "science" piled on the misinterpretation of what some(unidentified) official said in a news report five days after 911 when NO ONE KNEW WHERE THE CONCRETE WAS OR IT'S CONDITION. Yet truthers still claim ALL the concrete was "dustified" and try to calculate the energy required to do that AS IF IT WAS A SCIENTIFIC FACT.
This, of course, is only a single point in the massive pile of CRAP that is the so called"scholars" sites and what passes as "research" there, but one man could spend his entire life pointing out others and it is basically not worthwhile doing so.
Grumpy
QUOTE
http://journalof911studies.com/letters.html
Collapse Time Calculations for WTC 1, Kenneth Kuttler, Professor of Mathematics
Collapse Time Calculations for WTC 1, Kenneth Kuttler, Professor of Mathematics
Here is an example of what passes for "scholarship" on this site
in "Estimates for time to collapse of WTC1" it states...
"In [10]it states: Virtually all the concrete (an estimated 100,000
tons in each tower) on every floor was pulverized into a very fine dust, a phenomenon that requires enormous
energy and could not be caused by gravity alone; workers can't even find concrete.""
As if this was a scientifically proven fact. It's reference is another paper on this "scholarly" site...
Why Did the Trade Center Skyscrapers Collapse?
by Morgan Reynolds
"Virtually all the concrete (an estimated 100,000 tons in each tower) on every floor was pulverized into a very fine dust, a phenomenon that requires enormous energy and could not be caused by gravity alone ("…workers can’t even find concrete. ‘It’s all dust,’ [the official] said")."
Which references this ABC News site...
http://911research.wtc7.net/cache/disinfo/...osurvivors.html
And a report on survivors dated Sept 16, 2001 in which is the following paragraph...
"Rescue workers have been searching around the clock for survivors of the twin towers disaster. But the efforts remain painstakingly difficult and tumultuous. One official said that workers can't even find concrete. "It's all dust," he said."
An unattributed quote in a news report five days after the event(and weeks before they found the concrete rubble(not pulverized) in the basements) becomes a scientific fact because it is referenced in another "scholar's" paper??? Who is the "one official" and did he know that the concrete would be found weeks later in the basement??? Had he conducted a scientific investigation of the whereabouts of the concrete, or was he just expressing his frustration about being unable to find any survivors???
This is CRAP "science" piled on other CRAP "science" piled on the misinterpretation of what some(unidentified) official said in a news report five days after 911 when NO ONE KNEW WHERE THE CONCRETE WAS OR IT'S CONDITION. Yet truthers still claim ALL the concrete was "dustified" and try to calculate the energy required to do that AS IF IT WAS A SCIENTIFIC FACT.
This, of course, is only a single point in the massive pile of CRAP that is the so called"scholars" sites and what passes as "research" there, but one man could spend his entire life pointing out others and it is basically not worthwhile doing so.
Grumpy
Interesting misquote by Kuttler.
What Kuttler wrote:
As to the speed of collapse of WTC1, it looks like it came down in about 15 seconds from the time the antenna started to sink. Smaller figures have been put forth, however. The figure given by NIST [6] for the top panels of the building to hit the ground is 11 seconds. They based this on "precise timing of initiation of collapse from video evidence and also on seismic signals recorded at Palisades N.Y."
Later on in the paper Kuttler then claims that this 11 seconds is the OFFICIAL NIST time:
It is seen that all these Figures for collapse of WTC1 are longer than the official NIST figure of 11 seconds ..... (start of page 5)
But that is CLEARLY not what NIST said:
NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1.
But the FIRST EXTERIOR panels to strike the ground would have most likely come from ~94th floor (or even lower)
Kuttler KNOWS that NIST never gave an OFFICIAL collapse time because as he says on the first page of his report:
The time of collapse was not analyzed by NIST in their report
Its hard to tell if Kuttler is being SLOPPY or DISHONEST, but changing the WORDING from FIRST to TOP, and then claiming that this is an "official time" certainly smacks of the LATTER.
Also another important piece left out of the NIST statement:
From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
Arthur
What Kuttler wrote:
As to the speed of collapse of WTC1, it looks like it came down in about 15 seconds from the time the antenna started to sink. Smaller figures have been put forth, however. The figure given by NIST [6] for the top panels of the building to hit the ground is 11 seconds. They based this on "precise timing of initiation of collapse from video evidence and also on seismic signals recorded at Palisades N.Y."
Later on in the paper Kuttler then claims that this 11 seconds is the OFFICIAL NIST time:
It is seen that all these Figures for collapse of WTC1 are longer than the official NIST figure of 11 seconds ..... (start of page 5)
But that is CLEARLY not what NIST said:
NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1.
But the FIRST EXTERIOR panels to strike the ground would have most likely come from ~94th floor (or even lower)
Kuttler KNOWS that NIST never gave an OFFICIAL collapse time because as he says on the first page of his report:
The time of collapse was not analyzed by NIST in their report
Its hard to tell if Kuttler is being SLOPPY or DISHONEST, but changing the WORDING from FIRST to TOP, and then claiming that this is an "official time" certainly smacks of the LATTER.
Also another important piece left out of the NIST statement:
From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
Arthur
The most interesting thing is indeed the demolition wave hitting ground zero. I didn't know that NIST base that 11 seconds on those to panels, of course you can see from video evidence that it should be at least 14 seconds for wtc2, for wtc1 it is harder to see as far as I know. The part that hits the floor first should indeed be the lower part of the top block falling in air because everything else (ejected later) goes slower than that even if it got a downward velocity component. The only possibility is that if something from below hits the ground first that then ejected mass again bounces with the ejected stuff from the top block and collides in air again, and there is of course rotation. But this all is not the interesting part, the demolition wave's behaviour is the most important thing when looking at everything after collapse initiation.
QUOTE (einsteen+May 12 2007, 04:29 PM)
But after a few months here nobody could explain how this model would behave, ok we've seen tons of videos and we all see how the outside behaves, what happens inside the building? How does a top block that still contains trusses, perimeter and core columns fall into the building ? If you say it falls on the building, ok then and then you only have to explain how your model works.
What would be holding up the building with most or all of the columns disconnected from each other through the front? If things like that didn't matter, we could put up buildings with the columns resting on the concrete floor slabs instead of being concentric with the other columns. A building like that wouldn't stand in a static state and certainly not during a collapse. Columns of one block would be punching through the concrete floor slabs of the other block. After a few impacts there would be a pile of falling mass collapsing the floors between the core and perimeter on its own. At that point, what happened to the upper block wouldn't matter much in terms of keeping the collapse going but it would still have some effect on the speed of the front.
It would be great to clearly see what happened within the footprint inside the dust shroud. There's some evidence at the end of the collapses were portions of the cores were still standing, more so for the south tower where the core survived to about half the tower height and appear to have most of its length in the north-south direction and depth in the east-west direction. Portions of the cores were strong enough in the lower half of the towers to survive briefly even after the main floors collapsed.
QUOTE (Grumpy+May 10 2007, 02:13 PM)
Their final report on 7 is not yet out, so your criticism is premature and irrelivant to 1 and 2.
With Applied Research Associates' mandate that they aren't allowed to look at floors 1 through 7 and 47, I'm sure they'll get to the bottom of what happened to WTC 7.
Actually, your posts were so full of disinformation, lies and logic bereft arguements that one hardly knows where to start digging. A perfect example of the old saw, "If you can't argue with wit, dazzle them with BS".
Logical Fallacy: Ad hominem
http://www.nizkor.org/features/fallacies/ad-hominem.html
This is also an example of another logical fallacy: argument by assertion, i.e., asserting a point without proving it.
Logical Fallacy: Ad hominem
http://www.nizkor.org/features/fallacies/ad-hominem.html
This is also an example of another logical fallacy: argument by assertion, i.e., asserting a point without proving it.
As just one example...
That is just a lie...
April 09, 2006
Dear Editor,
Blah, blah, blah...
D. Allan Firmage
Sorry, I was referring to engineers that have actually produced scientific papers that at least make some sort of attempt to back up their claims, not unsubstantiated opinion pieces.
We can file this one in the same circular file as the Blanchard paper that you and your fellow travelers are fond of appealing to for the same reasons:
*Appeals to authority.
*Argument by assertion (i.e., asserting a point without proving it). "It's true because I said so."
Most engineers have simular opinions, the damage done by the impacts was severe and the weakening by subsiquent fires all that is needed to explain the collapses.
Not those who have produced scientific papers where there is an attempt to actually back up their assertions.
Since the most extensive analysis to date on the damage caused by the impacts has been done by NIST, and you consider their report to be your Bible, let's focus on it.
See NCSTAR 1-2B for the following two paragraphs:
NIST's "base" case was based on "a best estimate of all input parameters (based on photographic and video evidence, material testing, and data in the open literature)" was the "best match to the observed data", and "the calculated and observed damage in the impact zone [for WTC 1] were in good agreement."
For their base case for WTC 2: "The calculated and observed geometry and magnitude of the impact damage were in good agreement. That served to partially validate the geometry of the aircraft model, including the aircraft orientation, trajectory, and flight distortions of the wings. Agreement of both the mode and magnitude of the impact partially validated the constitutive and damage modeling of the aircraft and exterior wall of the tower."
Even though NIST's base case best matched the observed date, even in their most severe case, "the global analysis results showed that WTC 1 did not collapse following aircraft impact, as was observed, and had considerable reserve capacity" and after the impact, "only two columns had a demand-to-capacity ratio greater than 1.0" (i.e., exceeded their capacity). (NCSTAR 1-6, p. 240)
The reason for this (as you can see from the same page): "The core columns were loaded to approximately 50 percent of their capacity prior to impact, and the exterior columns were loaded to approximately 20 percent of their capacity. The exterior columns were capable of large load transfers from the core columns."
Ergo, even using NIST's most severe estimate of impact damage, your assertion that the end result in terms of the structure's integrity was "severe" is completely asinine.
But since NIST's base case was what best matched the observable data, let's return to it. The problem with NIST's base case was that even that scenario overestimated the likely damage to the core columns. For the base case for WTC 1, three core columns were severed and four were severely damaged.
However:
"The residual velocity and mass of the engine after penetration of the exterior wall was sufficient to fail a core column in a direct impact condition. Interaction with additional interior building contents prior to impact or a misaligned impact against the core column could change this result." (NCSTAR 1-2B, p. 382)
So an impact by the heaviest and most dense part of the aircraft, the engine, would cause a single core column to fail if struck directly and if the impact was perfectly aligned. In WTC 2 one of the engines exited the building without significant obstruction (NCSTAR 1-2B, p. 390), so that leaves at most, one of the core columns in WTC 2 and two in WTC 1 failing due to being struck by an engine.
What caused the rest of the columns in NIST's base case to fail on impact? The lower density fuselage?
For WTC 1:
"The forward fuselage structures were severely damaged both from the penetration through the exterior columns and the penetration of the 96th floor slab that sliced the fuselage structures in half." (NCSTAR 1-2B, p. 201)
"At 0.3 s after impact…the airframe was mostly broken up." (NCSTAR 1-2B, p. 206)
"The fuselage structures were severely damaged both from the penetration through the exterior columns and the penetration of the 96th floor slab that sliced the fuselage structures in half. The downward trajectory of the aircraft structures caused the airframe to collapse against the floor." (NCSTAR 1-2B, p. 385)
For WTC 2:
"The forward fuselage structures were severely damaged both from the penetration through the exterior columns and the penetration of the 81st floor slab that sliced the fuselage structures in half. The downward trajectory of the aircraft structures caused the airframe to collapse against the floor…" (NCSTAR 1-2B, p. 234)
"At 0.2 s after impact…the airframe was mostly broken up." (NCSTAR 1-2B, p. 234)
With Applied Research Associates' mandate that they aren't allowed to look at floors 1 through 7 and 47, I'm sure they'll get to the bottom of what happened to WTC 7.
QUOTE
Actually, your posts were so full of disinformation, lies and logic bereft arguements that one hardly knows where to start digging. A perfect example of the old saw, "If you can't argue with wit, dazzle them with BS".
Logical Fallacy: Ad hominem
http://www.nizkor.org/features/fallacies/ad-hominem.html
This is also an example of another logical fallacy: argument by assertion, i.e., asserting a point without proving it.
QUOTE (->
| QUOTE |
Actually, your posts were so full of disinformation, lies and logic bereft arguements that one hardly knows where to start digging. A perfect example of the old saw, "If you can't argue with wit, dazzle them with BS". |
Logical Fallacy: Ad hominem
http://www.nizkor.org/features/fallacies/ad-hominem.html
This is also an example of another logical fallacy: argument by assertion, i.e., asserting a point without proving it.
As just one example...
That is just a lie...
April 09, 2006
Dear Editor,
Blah, blah, blah...
D. Allan Firmage
Sorry, I was referring to engineers that have actually produced scientific papers that at least make some sort of attempt to back up their claims, not unsubstantiated opinion pieces.
We can file this one in the same circular file as the Blanchard paper that you and your fellow travelers are fond of appealing to for the same reasons:
*Appeals to authority.
*Argument by assertion (i.e., asserting a point without proving it). "It's true because I said so."
QUOTE
Most engineers have simular opinions, the damage done by the impacts was severe and the weakening by subsiquent fires all that is needed to explain the collapses.
Not those who have produced scientific papers where there is an attempt to actually back up their assertions.
Since the most extensive analysis to date on the damage caused by the impacts has been done by NIST, and you consider their report to be your Bible, let's focus on it.
See NCSTAR 1-2B for the following two paragraphs:
NIST's "base" case was based on "a best estimate of all input parameters (based on photographic and video evidence, material testing, and data in the open literature)" was the "best match to the observed data", and "the calculated and observed damage in the impact zone [for WTC 1] were in good agreement."
For their base case for WTC 2: "The calculated and observed geometry and magnitude of the impact damage were in good agreement. That served to partially validate the geometry of the aircraft model, including the aircraft orientation, trajectory, and flight distortions of the wings. Agreement of both the mode and magnitude of the impact partially validated the constitutive and damage modeling of the aircraft and exterior wall of the tower."
Even though NIST's base case best matched the observed date, even in their most severe case, "the global analysis results showed that WTC 1 did not collapse following aircraft impact, as was observed, and had considerable reserve capacity" and after the impact, "only two columns had a demand-to-capacity ratio greater than 1.0" (i.e., exceeded their capacity). (NCSTAR 1-6, p. 240)
The reason for this (as you can see from the same page): "The core columns were loaded to approximately 50 percent of their capacity prior to impact, and the exterior columns were loaded to approximately 20 percent of their capacity. The exterior columns were capable of large load transfers from the core columns."
Ergo, even using NIST's most severe estimate of impact damage, your assertion that the end result in terms of the structure's integrity was "severe" is completely asinine.
But since NIST's base case was what best matched the observable data, let's return to it. The problem with NIST's base case was that even that scenario overestimated the likely damage to the core columns. For the base case for WTC 1, three core columns were severed and four were severely damaged.
However:
"The residual velocity and mass of the engine after penetration of the exterior wall was sufficient to fail a core column in a direct impact condition. Interaction with additional interior building contents prior to impact or a misaligned impact against the core column could change this result." (NCSTAR 1-2B, p. 382)
So an impact by the heaviest and most dense part of the aircraft, the engine, would cause a single core column to fail if struck directly and if the impact was perfectly aligned. In WTC 2 one of the engines exited the building without significant obstruction (NCSTAR 1-2B, p. 390), so that leaves at most, one of the core columns in WTC 2 and two in WTC 1 failing due to being struck by an engine.
What caused the rest of the columns in NIST's base case to fail on impact? The lower density fuselage?
For WTC 1:
"The forward fuselage structures were severely damaged both from the penetration through the exterior columns and the penetration of the 96th floor slab that sliced the fuselage structures in half." (NCSTAR 1-2B, p. 201)
"At 0.3 s after impact…the airframe was mostly broken up." (NCSTAR 1-2B, p. 206)
"The fuselage structures were severely damaged both from the penetration through the exterior columns and the penetration of the 96th floor slab that sliced the fuselage structures in half. The downward trajectory of the aircraft structures caused the airframe to collapse against the floor." (NCSTAR 1-2B, p. 385)
For WTC 2:
"The forward fuselage structures were severely damaged both from the penetration through the exterior columns and the penetration of the 81st floor slab that sliced the fuselage structures in half. The downward trajectory of the aircraft structures caused the airframe to collapse against the floor…" (NCSTAR 1-2B, p. 234)
"At 0.2 s after impact…the airframe was mostly broken up." (NCSTAR 1-2B, p. 234)
Shagster, I'm not sure if I understand what you mean.
forgive the crappy animation, but this is my idea of the gravitational collapse, the above means that the core also breaks in parts otherwise it would stick through the building during the collapse which is not the case, because of symmetry in the situation there will be a crush-up and crush-down first, the slabs collide and merge together. This now is the effective collapsing mass that will repeat floors on its way down, the top part now falls after the merged floors, wants to go with free fall, does this until it touches the falling collapsing mass, therefore the crush-up is small during the crush-down. The perimeter columns are detached because they are the weakest parts.
The difference with the detachment of the trusses with the core columns is that this takes much more energy, it is more efficient to have them connected with the core while the core breaks into parts. If that is not the case then in fact the whole core will stand and not only a few stories at the bottom.
Since we also saw in 911eyewitness that complete > 400 meter sticks where still standing we can conclude that this model also is not complete, the solution then is that most of them break except some in the middle of the core (maybe those had no trusses connected ??)
The problem that I'm having is that there are two extreme situations depending on whether the trusses-connections fail first or the core itself. In the first situation a complete core should be there, this is a strict pancake collapse (goodness knows what NIST means with rejecting the pancake collapse) and the latter means that there is no standing core at all. That is the reason that I came with the above story, maybe in some cases the core fails during the fall and in other cases the connections.
forgive the crappy animation, but this is my idea of the gravitational collapse, the above means that the core also breaks in parts otherwise it would stick through the building during the collapse which is not the case, because of symmetry in the situation there will be a crush-up and crush-down first, the slabs collide and merge together. This now is the effective collapsing mass that will repeat floors on its way down, the top part now falls after the merged floors, wants to go with free fall, does this until it touches the falling collapsing mass, therefore the crush-up is small during the crush-down. The perimeter columns are detached because they are the weakest parts.
The difference with the detachment of the trusses with the core columns is that this takes much more energy, it is more efficient to have them connected with the core while the core breaks into parts. If that is not the case then in fact the whole core will stand and not only a few stories at the bottom.
Since we also saw in 911eyewitness that complete > 400 meter sticks where still standing we can conclude that this model also is not complete, the solution then is that most of them break except some in the middle of the core (maybe those had no trusses connected ??)
The problem that I'm having is that there are two extreme situations depending on whether the trusses-connections fail first or the core itself. In the first situation a complete core should be there, this is a strict pancake collapse (goodness knows what NIST means with rejecting the pancake collapse) and the latter means that there is no standing core at all. That is the reason that I came with the above story, maybe in some cases the core fails during the fall and in other cases the connections.
cerberus
The most dense and therefore most damaging portions of that type of aircraft are the main wing spar and the landing gear(on a volume/density basis), not the engines, and certainly not the thin and flimsy fuselage. The large size of the engines is due more to air passages than to structure(though the hot core is quite dense and strong). And you have not calculated the effects of 10,000 gallons of jet fuel traveling at 500 mph in your reckoning either. And, just as in a shotgun, the total energy of the total mass of that aircraft was(except for MINOR leakage) absorbed by the structure, it really makes no difference if it was intact or in a million pieces, that energy was the same.
Grumpy
The most dense and therefore most damaging portions of that type of aircraft are the main wing spar and the landing gear(on a volume/density basis), not the engines, and certainly not the thin and flimsy fuselage. The large size of the engines is due more to air passages than to structure(though the hot core is quite dense and strong). And you have not calculated the effects of 10,000 gallons of jet fuel traveling at 500 mph in your reckoning either. And, just as in a shotgun, the total energy of the total mass of that aircraft was(except for MINOR leakage) absorbed by the structure, it really makes no difference if it was intact or in a million pieces, that energy was the same.
Grumpy
QUOTE (Pierre-Normand+May 14 2007, 10:14 AM)
Is there some way (not vastly more complicatied[sic]) to solve this problem analytically for a column that has a linearly increasing density from top to bottom?
I would say non-uniform mass, by increasing the cross-section area, rather than changing the density. In any case, the mass increases downwards, which means the period increases proportionally so.
I currently have no nice way to solve this spring-mass problem for non-uniform mass. One way is to connect a series of mass-spring systems together, (416+21)/10.9728 = ~40 to represent all the members in a column. Set up all the equations and solve numerically. Not nice.
However, it is clear enough that the response near the top will no longer be represented by simply
1 - cos(Tt)
where T is the period and t is time.
My main point is that the vibrational modes of the lower portions of a column will soon begin the develop resistance to further movement downwards. That is enough to buckle whatever is the weakest member, given the very large load.
I would say non-uniform mass, by increasing the cross-section area, rather than changing the density. In any case, the mass increases downwards, which means the period increases proportionally so.
I currently have no nice way to solve this spring-mass problem for non-uniform mass. One way is to connect a series of mass-spring systems together, (416+21)/10.9728 = ~40 to represent all the members in a column. Set up all the equations and solve numerically. Not nice.
However, it is clear enough that the response near the top will no longer be represented by simply
1 - cos(Tt)
where T is the period and t is time.
My main point is that the vibrational modes of the lower portions of a column will soon begin the develop resistance to further movement downwards. That is enough to buckle whatever is the weakest member, given the very large load.
QUOTE (cerberus+May 14 2007, 02:48 PM)
Since the most extensive analysis to date on the damage caused by the impacts has been done by NIST, and you consider their report to be your Bible, let's focus on it.
Yup.
You use quote mining to try to imply that NIST engineers didn't think the damage was severe.
Quite the contrary.
NIST NCSTAR 1-6
Section E-1
Both the North and South towers of the World Trade Center were severely damaged by the impact ...
of from their FAQs
No building in the United States has ever been subjected to the massive structural damage and concurrent multi-floor fires that the towers experienced on Sept. 11, 2001.
Arthur
Yup.
You use quote mining to try to imply that NIST engineers didn't think the damage was severe.
Quite the contrary.
NIST NCSTAR 1-6
Section E-1
Both the North and South towers of the World Trade Center were severely damaged by the impact ...
of from their FAQs
No building in the United States has ever been subjected to the massive structural damage and concurrent multi-floor fires that the towers experienced on Sept. 11, 2001.
Arthur
QUOTE (David B. Benson+May 14 2007, 08:42 PM)
I would say non-uniform mass, by increasing the cross-section area, rather than changing the density. In any case, the mass increases downwards, which means the period increases proportionally so.
Yes, that is what I meant, sorry. I was thinking of the linear density of the column increasing, which is the result of an increase of the width/thickness of the steel plates/flanges, of course.
That seems reasonable indeed. It is one more thing Gordon Ross ought to take into account and doesn't. Thank you.
Yes, that is what I meant, sorry. I was thinking of the linear density of the column increasing, which is the result of an increase of the width/thickness of the steel plates/flanges, of course.
QUOTE
My main point is that the vibrational modes of the lower portions of a column will soon begin the develop resistance to further movement downwards. That is enough to buckle whatever is the weakest member, given the very large load.
That seems reasonable indeed. It is one more thing Gordon Ross ought to take into account and doesn't. Thank you.
QUOTE (Pierre-Normand+May 14 2007, 09:13 PM)
That seems reasonable indeed. ...
Upon reflection, it may be possible to use Laplace transform techniques on the cascade of harmonic oscillators to obtain a better approximation. I'll think about it some more over the next several days...
Upon reflection, it may be possible to use Laplace transform techniques on the cascade of harmonic oscillators to obtain a better approximation. I'll think about it some more over the next several days...
QUOTE (einsteen+May 14 2007, 08:09 PM)
The problem that I'm having is that there are two extreme situations depending on whether the trusses-connections fail first or the core itself. In the first situation a complete core should be there, this is a strict pancake collapse (goodness knows what NIST means with rejecting the pancake collapse) ...
(1) The truss connections were comparatively weak. A good approximation is that such fail first, when an actual floor was impacted.
(2) This does not mean the core would be able to stand. IMO, collapse initiation begins when an overload is transfered onto core columns. These buckle and the descent begins.
(3) NIST rejected pancaking as the collapse initiation cause. Instead, it is the buckling of the exterior walls leading to the overload on the core.
(4) I prefer the term bageling.
(1) The truss connections were comparatively weak. A good approximation is that such fail first, when an actual floor was impacted.
(2) This does not mean the core would be able to stand. IMO, collapse initiation begins when an overload is transfered onto core columns. These buckle and the descent begins.
(3) NIST rejected pancaking as the collapse initiation cause. Instead, it is the buckling of the exterior walls leading to the overload on the core.
(4) I prefer the term bageling.
QUOTE (Pierre-Normand+May 14 2007, 10:14 AM)
Is there some way (not vastly more complicated) to solve this problem analytically for a column that has a linearly increasing density from top to bottom?
Try this: Cross-sectional area is denoted by A; length is denoted by L, density by d. The effective mass is
m = d(AL)/3
The spring stiffness is
k = E(A/L).
Consider the ratio m/k used to determine the period of the mass-spring system:
m/k = (1/3)(d/E)(A/A)L^2 = (1/3)(d/E)L^2
which does not depend upon the cross-section area A. We conclude that the period of an extended mass-spring system is independent of the cross-sectional area anywhere along the length.
Seem correct to you?
Try this: Cross-sectional area is denoted by A; length is denoted by L, density by d. The effective mass is
m = d(AL)/3
The spring stiffness is
k = E(A/L).
Consider the ratio m/k used to determine the period of the mass-spring system:
m/k = (1/3)(d/E)(A/A)L^2 = (1/3)(d/E)L^2
which does not depend upon the cross-section area A. We conclude that the period of an extended mass-spring system is independent of the cross-sectional area anywhere along the length.
Seem correct to you?
QUOTE (adoucette+May 11 2007, 07:12 PM)
BS, those words are QUITE descriptive.
Those tests were the basis that only SFRM in the DIRECT PATH of the debris was considered to be removed and then ONLY if the debris had sufficient energy to create the damage described.
Those tests demonstrated that the SFRM was dislodged from flat surfaces only if it was directed in a very symmetrical fashion from a narrow range of angles of 0-40 degrees, and for the tests involving the small, round steel bars, the SFRM was only dislodged by direct impact with the shotgun pellets, leaving the SFRM immediately outside of the small blast pattern in place. This is a very narrow range of parameters required for the dislodging of the fire protection. Also, there are no assumptions that can be made based on these tests in regards to core columns protected by gypsum wallboard or a combination of gypsum wallboard and SFRM.
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "failed partitions in front of core columns" automatically translates into the fire protection being dislodged "over the floor height" from these columns by the necessary prerequisite of debris being directed very symmetrically at just the right 0-40 degree angle?
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "damaged or destroyed room furnishings (modular office workstations) adjacent to the exterior columns" automatically translates into the fire protection "on the inside face of the exterior columns in the same vicinity" being dislodged "over the floor height" by the necessary prerequisite of debris being directed very symmetrically at just the right 0-40 degree angle?
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "damaged or destroyed room furnishings (modular office workstations)" was able to transform itself into thousands of individual shotgun blasts covering the surface area of the floor trusses "in the same floor area" as the damaged or destroyed office furnishings?
Your continual reference to the 6,000 sq meter area has NO BASIS in what NIST did.
Sure it does, if you add up the surface area of the structural steel, using NIST's own assumption, in the areas depicted in their diagrams indicating dislodged fire protection.
Sure it does, if you add up the surface area of the structural steel, using NIST's own assumption, in the areas depicted in their diagrams indicating dislodged fire protection.
The MIT tests you reference didn't include anything BUT the structure, so it is WRONG to say that all of the Kinetic energy was consumed JUST in those areas. This is the reason that MIT overstated the amount of Column Damage though.
See NIST NCSTAR 1-2 Section 7.11.2 where NIST compares its study with the MIT study and points out that the MIT study "did not include the energy absorbed by internal tower contents"
This certainly doesn't change the total amount of kinetic energy available from the impact. So instead of all of the kinetic energy being consumed in the breaking of columns and the crushing of floors, a relatively small amount by comparison is allocated to pushing around and crushing cubicles and file cabinets.
Keep in mind that it's the columns and floor trusses left intact and supporting the load after the impact that are a concern as far as the dislodging of fire protection. How much fire protection is left on failed structural members is irrelevant. In order to arrive at the kinetic energy available for widely dislodging the fireproofing across multiple floors, we would first subtract the kinetic energy consumed in breaking columns and crushing floors. That doesn't leave us very much available to push some office contents around, and even then, you can't automatically assume that kinetic energy available to push office contents around is going to be available to be directed very symmetrically at just the right angles and at just the right spots to dislodge fire protection.
This brings up a good question though. How did the impact debris strip the fire protection from the columns and floor trusses in the areas of concern and leave the workstations in place in the same areas to be utilized as fuel?
Those tests were the basis that only SFRM in the DIRECT PATH of the debris was considered to be removed and then ONLY if the debris had sufficient energy to create the damage described.
Those tests demonstrated that the SFRM was dislodged from flat surfaces only if it was directed in a very symmetrical fashion from a narrow range of angles of 0-40 degrees, and for the tests involving the small, round steel bars, the SFRM was only dislodged by direct impact with the shotgun pellets, leaving the SFRM immediately outside of the small blast pattern in place. This is a very narrow range of parameters required for the dislodging of the fire protection. Also, there are no assumptions that can be made based on these tests in regards to core columns protected by gypsum wallboard or a combination of gypsum wallboard and SFRM.
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "failed partitions in front of core columns" automatically translates into the fire protection being dislodged "over the floor height" from these columns by the necessary prerequisite of debris being directed very symmetrically at just the right 0-40 degree angle?
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "damaged or destroyed room furnishings (modular office workstations) adjacent to the exterior columns" automatically translates into the fire protection "on the inside face of the exterior columns in the same vicinity" being dislodged "over the floor height" by the necessary prerequisite of debris being directed very symmetrically at just the right 0-40 degree angle?
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "damaged or destroyed room furnishings (modular office workstations)" was able to transform itself into thousands of individual shotgun blasts covering the surface area of the floor trusses "in the same floor area" as the damaged or destroyed office furnishings?
QUOTE
Your continual reference to the 6,000 sq meter area has NO BASIS in what NIST did.
Sure it does, if you add up the surface area of the structural steel, using NIST's own assumption, in the areas depicted in their diagrams indicating dislodged fire protection.
QUOTE (->
| QUOTE |
Your continual reference to the 6,000 sq meter area has NO BASIS in what NIST did. |
Sure it does, if you add up the surface area of the structural steel, using NIST's own assumption, in the areas depicted in their diagrams indicating dislodged fire protection.
The MIT tests you reference didn't include anything BUT the structure, so it is WRONG to say that all of the Kinetic energy was consumed JUST in those areas. This is the reason that MIT overstated the amount of Column Damage though.
See NIST NCSTAR 1-2 Section 7.11.2 where NIST compares its study with the MIT study and points out that the MIT study "did not include the energy absorbed by internal tower contents"
This certainly doesn't change the total amount of kinetic energy available from the impact. So instead of all of the kinetic energy being consumed in the breaking of columns and the crushing of floors, a relatively small amount by comparison is allocated to pushing around and crushing cubicles and file cabinets.
Keep in mind that it's the columns and floor trusses left intact and supporting the load after the impact that are a concern as far as the dislodging of fire protection. How much fire protection is left on failed structural members is irrelevant. In order to arrive at the kinetic energy available for widely dislodging the fireproofing across multiple floors, we would first subtract the kinetic energy consumed in breaking columns and crushing floors. That doesn't leave us very much available to push some office contents around, and even then, you can't automatically assume that kinetic energy available to push office contents around is going to be available to be directed very symmetrically at just the right angles and at just the right spots to dislodge fire protection.
This brings up a good question though. How did the impact debris strip the fire protection from the columns and floor trusses in the areas of concern and leave the workstations in place in the same areas to be utilized as fuel?
QUOTE (cerberus+May 14 2007, 11:05 PM)
How did the impact debris strip the fire protection from the columns and floor trusses in the areas of concern and leave the workstations in place in the same areas to be utilized as fuel?
Didn't happen that way, according to NIST. After the aircraft impact, the office materials were redistributed along the aircraft path. There are visuals demonstrating this.
Didn't happen that way, according to NIST. After the aircraft impact, the office materials were redistributed along the aircraft path. There are visuals demonstrating this.
QUOTE (adoucette+May 11 2007, 07:19 PM)
In all that, not one thing that has ANYTHING to do with 9/11.
Well, according to Sibel, it has everything to do with it. It's all about following the money (i.e., criminal investigation 101). But as long as there are multiple gag orders in place and the State Secrets privilege is being invoked to prevent any court cases from going forward, I guess we'll never know.
Of course, according to the 9/11 commission regarding the origin of the money used for the 9/11 attacks: "Ultimately the question is of little practical significance."
http://www.9-11commission.gov/report/911Report_Ch5.htm
As to Siebel, the State's Secret Privilige is NOT a gag order and ONLY applies to testimony in a court,
Correct.
Correct.
she can friggin write a book about what she knows.
No, she can't, unless she wants to go straight to jail. She also has multiple gag orders that have been placed on her by the Justice Department, which prevent her from discussing the details in public. More gag orders than anybody in history.
I have plenty of concern about anyone breaking the law, and IF I knew of people that were selling state secrets you can be sure I would get the word out.
Its INTERESTING that all the people you claim KNOW about it, actually do NOTHING.
That's because between the State Secrets privilege invoked by the State Department and Pentagon and the multiple gag orders, there isn't anything that can be done. Duh...
Actually video evidence is quite reliable. You know the distance by knowing the height. Then it's just a matter of timing how long it took for the top to reach the bottom. There are videos that show the entire collapse (I have seen one) and you can tell very distinctly when it begins to collapse (it happens out of the blue rather than gradual showing signs of collapse before it did). Between knowing the distance and time to travel the distance you can find out that the top of the building fell in a near free fall. It actually fell equivalently to demo'ed buildings.
The same beams found at the bottom that supported the entire building extended all the way up. So if a section of beam is strong enough to support the entire building it will most certainly be strong enough to support 30% of the total weight. It would take a lot of heat and burning time to weaken the steel and even if it did then it would topple over toward the weaker side which it didn't.
The temperature of the fires were not hot enough and did not burn long enough even if they were hot enough. The second tower received less damage and almost all the fuel of the plane (hottest burning substance there) burned up in one big fireball outside the adjacent side since the plane only clipped the corner.
Well, according to Sibel, it has everything to do with it. It's all about following the money (i.e., criminal investigation 101). But as long as there are multiple gag orders in place and the State Secrets privilege is being invoked to prevent any court cases from going forward, I guess we'll never know.
Of course, according to the 9/11 commission regarding the origin of the money used for the 9/11 attacks: "Ultimately the question is of little practical significance."
http://www.9-11commission.gov/report/911Report_Ch5.htm
QUOTE
As to Siebel, the State's Secret Privilige is NOT a gag order and ONLY applies to testimony in a court,
Correct.
QUOTE (->
| QUOTE |
As to Siebel, the State's Secret Privilige is NOT a gag order and ONLY applies to testimony in a court, |
Correct.
she can friggin write a book about what she knows.
No, she can't, unless she wants to go straight to jail. She also has multiple gag orders that have been placed on her by the Justice Department, which prevent her from discussing the details in public. More gag orders than anybody in history.
QUOTE
I have plenty of concern about anyone breaking the law, and IF I knew of people that were selling state secrets you can be sure I would get the word out.
QUOTE (->
| QUOTE |
I have plenty of concern about anyone breaking the law, and IF I knew of people that were selling state secrets you can be sure I would get the word out. |
Its INTERESTING that all the people you claim KNOW about it, actually do NOTHING.
That's because between the State Secrets privilege invoked by the State Department and Pentagon and the multiple gag orders, there isn't anything that can be done. Duh...
Eduardo E. Rodriguez & Gabriel A. Gesnouin, Effective Mass of an Oscillating Spring, The Physics Teacher V. 45, 100--103 (2007 Feb) show, by experiments, that for coiled springs oscillating with only self-weight, the effective mass reduction factor is about 0.42, not (1/3).
This only make a small difference in the period, the change being sqrt(3x0.42) = 1.122 the previously stated times for the period.
This only make a small difference in the period, the change being sqrt(3x0.42) = 1.122 the previously stated times for the period.
cerberus
You are a joke, "follow the money" my big ol' butt!!!
The 19 hijackers responsible for 911 were operating on Ben Laden's credit cards(and those of other Saudi nationals). Siebel MAY know of other crimes, but she simply wasn't in on that pipeline. If she knows about criminals in the administration, more power to her(I'm a lifetime member of the ACLU), but to stretch that to something to do with 911 is a stretch too far.
And you wonder why we see the "troothers" as a bunch of paranoid halfwits who will cling to any little scrap they think will support their delusions. It's really pretty pathetic, actually.
Grumpy
You are a joke, "follow the money" my big ol' butt!!!
The 19 hijackers responsible for 911 were operating on Ben Laden's credit cards(and those of other Saudi nationals). Siebel MAY know of other crimes, but she simply wasn't in on that pipeline. If she knows about criminals in the administration, more power to her(I'm a lifetime member of the ACLU), but to stretch that to something to do with 911 is a stretch too far.
And you wonder why we see the "troothers" as a bunch of paranoid halfwits who will cling to any little scrap they think will support their delusions. It's really pretty pathetic, actually.
Grumpy
QUOTE
Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
Actually video evidence is quite reliable. You know the distance by knowing the height. Then it's just a matter of timing how long it took for the top to reach the bottom. There are videos that show the entire collapse (I have seen one) and you can tell very distinctly when it begins to collapse (it happens out of the blue rather than gradual showing signs of collapse before it did). Between knowing the distance and time to travel the distance you can find out that the top of the building fell in a near free fall. It actually fell equivalently to demo'ed buildings.
The same beams found at the bottom that supported the entire building extended all the way up. So if a section of beam is strong enough to support the entire building it will most certainly be strong enough to support 30% of the total weight. It would take a lot of heat and burning time to weaken the steel and even if it did then it would topple over toward the weaker side which it didn't.
The temperature of the fires were not hot enough and did not burn long enough even if they were hot enough. The second tower received less damage and almost all the fuel of the plane (hottest burning substance there) burned up in one big fireball outside the adjacent side since the plane only clipped the corner.
QUOTE (adoucette+May 11 2007, 07:28 PM)
You are mixing apples and oranges.
The oven tests were to find out if the Trusses as built with the SPECIFIED 1/2" of SFRM applied AS SPECIFIED, met the ASTM fire rating that they were supposed to have.
Not really. There were also tests done involving .75 inch thick SFRM. And the standard ASTM E119-length tests "had no SFRM on the bridging trusses nor on the underside of the metal deck." (NCSTAR 1-6, p. lxxiii)
The problem here is that the SFRM had been upgraded over the entire impact zone for WTC 1 (floors 92-100 and 102) and one of the floors in the impact zone for WTC 2 (floors 77, 78, 88, 89, 92, 96 and 97) (NCSTAR 1-6, p. 20) and the upgraded insulation was "thermally equivalent to a uniform thickness of 2.2 in." (NCSTAR 1-6, p. lxxi) with "the overall average thickness determined from the 256 individual measurements was found to be 2.5 in." (NCSTAR 1-6, p. 25)
Also of note:
"The average of the adhesive and cohesive strengths was found to be 409 psf for the ¾ in. SFRM, and the average is 622 psf for the 1-1/2 in. SFRM. These values are considerably greater than the manufacturer's published strength of 295 psf, obtained using the ASTM E 736 method under laboratory conditions." (NCSTAR 1-6, p. 35)
Also, you are not entirely correct about the purpose of the tests. They were used to "validate and provide guidance to the development of the floor models and to the interpretation of analysis results." (NCSTAR 1-6, p. 5)
They didn't, instead of the specified 2 hour rating they only managed 45 minutes.
Don't lie. The Canadian tests involving the full scale models and the .75 inch layer of SFRM were fire rated at 2 hours for the unrestrained floor system and 1.5 hours for the restrained floor system. And as stated above, the upgraded fire protection was 3X the thickness of that used in the tests.
Even so and more importantly, under twice the floor loads known to have existed and fire durations much longer than those of the short-lived WTC fires, and fire protection that was either non-existent or much less robust than that installed:
"Finding 7: All four tests demonstrated that the floor assemblies were capable of sagging without failure. The unrestrained test, which had two 0.875 in. bolts fastening the main truss to the truss seats, did not sag sufficiently to bear on the bolts." (NCSTAR 1-6, p. lxxii)
"Finding 8: All four test assemblies supported their full design load under standard fire conditions for two hours without collapse." (NCSTAR 1-6, p. lxxii)
Don't lie. The Canadian tests involving the full scale models and the .75 inch layer of SFRM were fire rated at 2 hours for the unrestrained floor system and 1.5 hours for the restrained floor system. And as stated above, the upgraded fire protection was 3X the thickness of that used in the tests.
Even so and more importantly, under twice the floor loads known to have existed and fire durations much longer than those of the short-lived WTC fires, and fire protection that was either non-existent or much less robust than that installed:
"Finding 7: All four tests demonstrated that the floor assemblies were capable of sagging without failure. The unrestrained test, which had two 0.875 in. bolts fastening the main truss to the truss seats, did not sag sufficiently to bear on the bolts." (NCSTAR 1-6, p. lxxii)
"Finding 8: All four test assemblies supported their full design load under standard fire conditions for two hours without collapse." (NCSTAR 1-6, p. lxxii)
The deflections were also quite a bit more than the 3" you claim.
See NIST NCSTAR 1-6B Figure 6-9 pg where in both Test 1 and 2 the deflection OF INSULATED TRUSSES exceeded one foot (15" in Test 1) and in both cases, the test was halted because either the deflection became to large to measure or because of imminent collapse. See NIST NCSTAR 1-6 Table 5-5.
This is true. The 3 inches was the minimum for the tests. 15 inches was the maximum at the two hour mark (compared to the short-lived WTC fires), and it was for the restrained floor system with the fire rating of 1.5 hours. Even 15 inches is significantly less than the 42 inches assumed by NIST in their computer simulation. And again...
...despite twice the floor loads known to have existed and fire durations much longer than those of the short-lived WTC fires, and fire protection that was either non-existent or much less robust than that installed:
"Finding 7: All four tests demonstrated that the floor assemblies were capable of sagging without failure. The unrestrained test, which had two 0.875 in. bolts fastening the main truss to the truss seats, did not sag sufficiently to bear on the bolts." (NCSTAR 1-6, p. lxxii)
"Finding 8: All four test assemblies supported their full design load under standard fire conditions for two hours without collapse." (NCSTAR 1-6, p. lxxii)
The other tests/experiments/modelling NIST did were to determine how hot the trusses IN THE CONDITIONS within the tower would become and what would happen to them.
Those tests couldn't be done in the oven because no oven would support that kind of damage to the truss.
You mean the computer simulations. As quoted above, one of the purposes of the physical tests of the floor assemblies was to inform the computer simulation.
As you can see in the same pages you are referring me to, the floor assemblies in the test furnaces reached temperatures of 1000 C and still held up remarkably well, (again) despite being under twice the floor load known to have existed in the WTC and for much longer than the short-lived WTC fires... with significantly degraded fire protection compared to that installed on all of the relevant floors in WTC 1 and one of the floors in WTC 2.
Of course, you have no evidence that the steel temperatures in the WTC reached anywhere near this temperature, and the steel samples from the impact and fire zones that NIST analyzed demonstrate temperatures of ~250 C.
It is interesting to note that in one of NIST's computer simulations "with the thermally equivalent 2.2 in. of fireproofing intact on the south trusses, these trusses did not heat appreciably, and the floors did not sag." (NCSTAR 1-6, p. 215)
You mean the computer simulations. As quoted above, one of the purposes of the physical tests of the floor assemblies was to inform the computer simulation.
As you can see in the same pages you are referring me to, the floor assemblies in the test furnaces reached temperatures of 1000 C and still held up remarkably well, (again) despite being under twice the floor load known to have existed in the WTC and for much longer than the short-lived WTC fires... with significantly degraded fire protection compared to that installed on all of the relevant floors in WTC 1 and one of the floors in WTC 2.
Of course, you have no evidence that the steel temperatures in the WTC reached anywhere near this temperature, and the steel samples from the impact and fire zones that NIST analyzed demonstrate temperatures of ~250 C.
It is interesting to note that in one of NIST's computer simulations "with the thermally equivalent 2.2 in. of fireproofing intact on the south trusses, these trusses did not heat appreciably, and the floors did not sag." (NCSTAR 1-6, p. 215)
But if you think that NIST's fire tests are bogus all you have to do is PROVE IT.
I don't think NIST's tests of the floor assemblies were bogus, although they could certainly have been improved upon. I find them to be quite informative.
Oh and those Corus Tests you CLAIM showed that steel didn't get that hot in a fire.
NOPE
JUST THE OPPOSITE
http://www.mace.manchester.ac.uk/project/r...stBRE215741.pdf
See Fig 23 Mid Span Beam Temps.
Note how ALL of them are OVER 800 C
That isn't the Corus tests I was referring to, but thanks for bringing this to my attention as it is another line of evidence that contradicts your beliefs.
As FEMA points out in Appendix A of their WTC report, Overview of Fire Protection in Buildings:
"In the mid-1990s British Steel and the Building Research Establishment performed a series of six experiments at Cardington to investigate the behavior of steel frame buildings. These experiments were conducted in a simulated, eight-story building. Secondary steel beams were not protected. Despite the temperature of the steel beams reaching 800-900° C (1,500-1,700° F) in three of the tests (well above the traditionally assumed critical temperature of 600° C (1,100° F), no collapse was observed in any of the six experiments."
http://www.fema.gov/pdf/library/fema403_apa.pdf
Hoisted on your own petard.
Again.
Arthur
Yes, that was the "as applied" test. But if you read the actual DETAIL report NIST NCSTAR 1-6B 1.2 PURPOSE of the Standard Fire tests its pretty clear, since 3 of the 4 bullets are all about the question of the AS SPECIFIED 1/2"
So when you say "Don't lie" in regards to my quote it is YOU that are LYING since my comment was CLEARLY referring to the AS SPECIFIED test and it achieved the 45 minute rating that I stated.
See Table 5-5 pg 96 of NCSTAR 1-6b.
Yes, that was the "as applied" test. But if you read the actual DETAIL report NIST NCSTAR 1-6B 1.2 PURPOSE of the Standard Fire tests its pretty clear, since 3 of the 4 bullets are all about the question of the AS SPECIFIED 1/2"
So when you say "Don't lie" in regards to my quote it is YOU that are LYING since my comment was CLEARLY referring to the AS SPECIFIED test and it achieved the 45 minute rating that I stated.
See Table 5-5 pg 96 of NCSTAR 1-6b.
The problem here is that the SFRM had been upgraded ...
The PROBLEM is: What part of the SFRM had been disloged by the impact DO YOU NOT UNDERSTAND????
You keep repeating this over and over, that the insulation in the tests was less than in the towers, but the purpose of the test was NOT to duplicate the conditions in the towers.
But the MODELS did duplicate those conditions. So they had the thicker upgraded SFRM, they had the overspray on the deck though none was specified etc etc.
You go on about the tests indicating the floors didn't fail, but they didn't in the model EITHER. That's the point, they provided a PULL IN force on the perimeter columns that they wouldn't have if they HAD failed.
So once again, all you do it compare apples to oranges and take things out of context.
Seems a pattern with CT'ers, they just don't seem to be able to get the FACTs straight.
Arthur
The oven tests were to find out if the Trusses as built with the SPECIFIED 1/2" of SFRM applied AS SPECIFIED, met the ASTM fire rating that they were supposed to have.
Not really. There were also tests done involving .75 inch thick SFRM. And the standard ASTM E119-length tests "had no SFRM on the bridging trusses nor on the underside of the metal deck." (NCSTAR 1-6, p. lxxiii)
The problem here is that the SFRM had been upgraded over the entire impact zone for WTC 1 (floors 92-100 and 102) and one of the floors in the impact zone for WTC 2 (floors 77, 78, 88, 89, 92, 96 and 97) (NCSTAR 1-6, p. 20) and the upgraded insulation was "thermally equivalent to a uniform thickness of 2.2 in." (NCSTAR 1-6, p. lxxi) with "the overall average thickness determined from the 256 individual measurements was found to be 2.5 in." (NCSTAR 1-6, p. 25)
Also of note:
"The average of the adhesive and cohesive strengths was found to be 409 psf for the ¾ in. SFRM, and the average is 622 psf for the 1-1/2 in. SFRM. These values are considerably greater than the manufacturer's published strength of 295 psf, obtained using the ASTM E 736 method under laboratory conditions." (NCSTAR 1-6, p. 35)
Also, you are not entirely correct about the purpose of the tests. They were used to "validate and provide guidance to the development of the floor models and to the interpretation of analysis results." (NCSTAR 1-6, p. 5)
QUOTE
They didn't, instead of the specified 2 hour rating they only managed 45 minutes.
Don't lie. The Canadian tests involving the full scale models and the .75 inch layer of SFRM were fire rated at 2 hours for the unrestrained floor system and 1.5 hours for the restrained floor system. And as stated above, the upgraded fire protection was 3X the thickness of that used in the tests.
Even so and more importantly, under twice the floor loads known to have existed and fire durations much longer than those of the short-lived WTC fires, and fire protection that was either non-existent or much less robust than that installed:
"Finding 7: All four tests demonstrated that the floor assemblies were capable of sagging without failure. The unrestrained test, which had two 0.875 in. bolts fastening the main truss to the truss seats, did not sag sufficiently to bear on the bolts." (NCSTAR 1-6, p. lxxii)
"Finding 8: All four test assemblies supported their full design load under standard fire conditions for two hours without collapse." (NCSTAR 1-6, p. lxxii)
QUOTE (->
| QUOTE |
They didn't, instead of the specified 2 hour rating they only managed 45 minutes. |
Don't lie. The Canadian tests involving the full scale models and the .75 inch layer of SFRM were fire rated at 2 hours for the unrestrained floor system and 1.5 hours for the restrained floor system. And as stated above, the upgraded fire protection was 3X the thickness of that used in the tests.
Even so and more importantly, under twice the floor loads known to have existed and fire durations much longer than those of the short-lived WTC fires, and fire protection that was either non-existent or much less robust than that installed:
"Finding 7: All four tests demonstrated that the floor assemblies were capable of sagging without failure. The unrestrained test, which had two 0.875 in. bolts fastening the main truss to the truss seats, did not sag sufficiently to bear on the bolts." (NCSTAR 1-6, p. lxxii)
"Finding 8: All four test assemblies supported their full design load under standard fire conditions for two hours without collapse." (NCSTAR 1-6, p. lxxii)
The deflections were also quite a bit more than the 3" you claim.
See NIST NCSTAR 1-6B Figure 6-9 pg where in both Test 1 and 2 the deflection OF INSULATED TRUSSES exceeded one foot (15" in Test 1) and in both cases, the test was halted because either the deflection became to large to measure or because of imminent collapse. See NIST NCSTAR 1-6 Table 5-5.
This is true. The 3 inches was the minimum for the tests. 15 inches was the maximum at the two hour mark (compared to the short-lived WTC fires), and it was for the restrained floor system with the fire rating of 1.5 hours. Even 15 inches is significantly less than the 42 inches assumed by NIST in their computer simulation. And again...
...despite twice the floor loads known to have existed and fire durations much longer than those of the short-lived WTC fires, and fire protection that was either non-existent or much less robust than that installed:
"Finding 7: All four tests demonstrated that the floor assemblies were capable of sagging without failure. The unrestrained test, which had two 0.875 in. bolts fastening the main truss to the truss seats, did not sag sufficiently to bear on the bolts." (NCSTAR 1-6, p. lxxii)
"Finding 8: All four test assemblies supported their full design load under standard fire conditions for two hours without collapse." (NCSTAR 1-6, p. lxxii)
QUOTE
The other tests/experiments/modelling NIST did were to determine how hot the trusses IN THE CONDITIONS within the tower would become and what would happen to them.
Those tests couldn't be done in the oven because no oven would support that kind of damage to the truss.
You mean the computer simulations. As quoted above, one of the purposes of the physical tests of the floor assemblies was to inform the computer simulation.
As you can see in the same pages you are referring me to, the floor assemblies in the test furnaces reached temperatures of 1000 C and still held up remarkably well, (again) despite being under twice the floor load known to have existed in the WTC and for much longer than the short-lived WTC fires... with significantly degraded fire protection compared to that installed on all of the relevant floors in WTC 1 and one of the floors in WTC 2.
Of course, you have no evidence that the steel temperatures in the WTC reached anywhere near this temperature, and the steel samples from the impact and fire zones that NIST analyzed demonstrate temperatures of ~250 C.
It is interesting to note that in one of NIST's computer simulations "with the thermally equivalent 2.2 in. of fireproofing intact on the south trusses, these trusses did not heat appreciably, and the floors did not sag." (NCSTAR 1-6, p. 215)
QUOTE (->
| QUOTE |
The other tests/experiments/modelling NIST did were to determine how hot the trusses IN THE CONDITIONS within the tower would become and what would happen to them. Those tests couldn't be done in the oven because no oven would support that kind of damage to the truss. |
You mean the computer simulations. As quoted above, one of the purposes of the physical tests of the floor assemblies was to inform the computer simulation.
As you can see in the same pages you are referring me to, the floor assemblies in the test furnaces reached temperatures of 1000 C and still held up remarkably well, (again) despite being under twice the floor load known to have existed in the WTC and for much longer than the short-lived WTC fires... with significantly degraded fire protection compared to that installed on all of the relevant floors in WTC 1 and one of the floors in WTC 2.
Of course, you have no evidence that the steel temperatures in the WTC reached anywhere near this temperature, and the steel samples from the impact and fire zones that NIST analyzed demonstrate temperatures of ~250 C.
It is interesting to note that in one of NIST's computer simulations "with the thermally equivalent 2.2 in. of fireproofing intact on the south trusses, these trusses did not heat appreciably, and the floors did not sag." (NCSTAR 1-6, p. 215)
But if you think that NIST's fire tests are bogus all you have to do is PROVE IT.
I don't think NIST's tests of the floor assemblies were bogus, although they could certainly have been improved upon. I find them to be quite informative.
QUOTE (Precursor562+May 15 2007, 01:32 AM)
Between knowing the distance and time to travel the distance you can find out that the top of the building fell in a near free fall.
Using the measured drops of both towers for the first few seconds provided by poster NEU-FONZE, the best estimates for the accelerations of both towers are
WTC 1: (2/3) g
WTC 2: (3/4) g
Neither is 'near free-fall' as determined by a robust test of statistical significance I posted about a few pages back.
Using the measured drops of both towers for the first few seconds provided by poster NEU-FONZE, the best estimates for the accelerations of both towers are
WTC 1: (2/3) g
WTC 2: (3/4) g
Neither is 'near free-fall' as determined by a robust test of statistical significance I posted about a few pages back.
QUOTE (adoucette+May 11 2007, 07:28 PM)
Oh and those Corus Tests you CLAIM showed that steel didn't get that hot in a fire.
NOPE
JUST THE OPPOSITE
http://www.mace.manchester.ac.uk/project/r...stBRE215741.pdf
See Fig 23 Mid Span Beam Temps.
Note how ALL of them are OVER 800 C
That isn't the Corus tests I was referring to, but thanks for bringing this to my attention as it is another line of evidence that contradicts your beliefs.
As FEMA points out in Appendix A of their WTC report, Overview of Fire Protection in Buildings:
"In the mid-1990s British Steel and the Building Research Establishment performed a series of six experiments at Cardington to investigate the behavior of steel frame buildings. These experiments were conducted in a simulated, eight-story building. Secondary steel beams were not protected. Despite the temperature of the steel beams reaching 800-900° C (1,500-1,700° F) in three of the tests (well above the traditionally assumed critical temperature of 600° C (1,100° F), no collapse was observed in any of the six experiments."
http://www.fema.gov/pdf/library/fema403_apa.pdf
QUOTE
Hoisted on your own petard.
Again.
Arthur
SO WHAT????
What part of the FIRES ALONE would not have caused the collapse of the WTC towers do you NOT understand?????
Sheesh.
Arthur
What part of the FIRES ALONE would not have caused the collapse of the WTC towers do you NOT understand?????
Sheesh.
Arthur
QUOTE (David B. Benson+May 14 2007, 09:41 PM)
(4) I prefer the term bageling.
I also like doughnuting ("do nothing").
I also like doughnuting ("do nothing").
QUOTE (Grumpy+May 13 2007, 12:19 PM)
quicklybraindead
Go ahead, attack the messenger since your "paper" and "firetruck" are simply indefensible, just quit trying to get Jesus to validate your lies
newton
Where is the evidence for explosives??? Explosions in the basement are easily seen to be fuel/air explosions caused by jet fuel, no evidence for other explosives put the lie to your and Craig's claims.
Besides, I'm not ridiculing religious beliefs, just those who abuse and misuse them for their own gain. Lying-for-Jesus is the height of hypocracy and IS NOT a Christian thing to do.
All analogies have a point where they no longer apply. Gordon's is a nonstarter from the beginning(the towers were tunnels, not solid). Mine deals only with the floors, not the core. The core was bypassed by the floors and fell due to their inability to stand the strain once the floors were not bracing them.
Grumpy
Messenger? Your "message" of late seems only to call people liars (with nothing to back up your lie).
That is not a "message", so hot air seems right on the money.
Oh, and you are wrong again on all accounts.
WITH ALL PRAYER AND PETITION PRAY AT ALL TIMES IN THE SPIRIT
Go ahead, attack the messenger since your "paper" and "firetruck" are simply indefensible, just quit trying to get Jesus to validate your lies
newton
Where is the evidence for explosives??? Explosions in the basement are easily seen to be fuel/air explosions caused by jet fuel, no evidence for other explosives put the lie to your and Craig's claims.
Besides, I'm not ridiculing religious beliefs, just those who abuse and misuse them for their own gain. Lying-for-Jesus is the height of hypocracy and IS NOT a Christian thing to do.
All analogies have a point where they no longer apply. Gordon's is a nonstarter from the beginning(the towers were tunnels, not solid). Mine deals only with the floors, not the core. The core was bypassed by the floors and fell due to their inability to stand the strain once the floors were not bracing them.
Grumpy
Messenger? Your "message" of late seems only to call people liars (with nothing to back up your lie).
That is not a "message", so hot air seems right on the money.
Oh, and you are wrong again on all accounts.
WITH ALL PRAYER AND PETITION PRAY AT ALL TIMES IN THE SPIRIT
QUOTE
There were also tests done involving .75 inch thick SFRM. And the standard ASTM E119-length tests "had no SFRM on the bridging trusses nor on the underside of the metal deck." (NCSTAR 1-6, p. lxxiii)
Yes, that was the "as applied" test. But if you read the actual DETAIL report NIST NCSTAR 1-6B 1.2 PURPOSE of the Standard Fire tests its pretty clear, since 3 of the 4 bullets are all about the question of the AS SPECIFIED 1/2"
So when you say "Don't lie" in regards to my quote it is YOU that are LYING since my comment was CLEARLY referring to the AS SPECIFIED test and it achieved the 45 minute rating that I stated.
See Table 5-5 pg 96 of NCSTAR 1-6b.
QUOTE (->
| QUOTE |
| There were also tests done involving .75 inch thick SFRM. And the standard ASTM E119-length tests "had no SFRM on the bridging trusses nor on the underside of the metal deck." (NCSTAR 1-6, p. lxxiii) |
Yes, that was the "as applied" test. But if you read the actual DETAIL report NIST NCSTAR 1-6B 1.2 PURPOSE of the Standard Fire tests its pretty clear, since 3 of the 4 bullets are all about the question of the AS SPECIFIED 1/2"
So when you say "Don't lie" in regards to my quote it is YOU that are LYING since my comment was CLEARLY referring to the AS SPECIFIED test and it achieved the 45 minute rating that I stated.
See Table 5-5 pg 96 of NCSTAR 1-6b.
The problem here is that the SFRM had been upgraded ...
The PROBLEM is: What part of the SFRM had been disloged by the impact DO YOU NOT UNDERSTAND????
You keep repeating this over and over, that the insulation in the tests was less than in the towers, but the purpose of the test was NOT to duplicate the conditions in the towers.
But the MODELS did duplicate those conditions. So they had the thicker upgraded SFRM, they had the overspray on the deck though none was specified etc etc.
You go on about the tests indicating the floors didn't fail, but they didn't in the model EITHER. That's the point, they provided a PULL IN force on the perimeter columns that they wouldn't have if they HAD failed.
So once again, all you do it compare apples to oranges and take things out of context.
Seems a pattern with CT'ers, they just don't seem to be able to get the FACTs straight.
Arthur
QUOTE (Pierre-Normand+May 15 2007, 02:37 AM)
I also like doughnuting ("do nothing").
deep.
no surprise.
deep.
no surprise.
QUOTE (adoucette+May 13 2007, 03:53 PM)
And you apparently failed in Biology.
You remind of a student I tutored when I was in graduate school, who seemed unable to solve the simplest of problems. It finally occurred to me that his brain did not seem to have a grasp of relative distance. So, I asked him, "If point A is far from point B, but point C is near point B, what can we say about the relationship between points A and C?"
He failed that test.
Before you make yet another of your not-so-omniscient remarks about the quality of this school, be aware that a fellow graduate student could easily read and comprehend 200 or 300 pages of linear algebra at a clip. Linear algebra may be the simplest abstract (proofs and theorems) course out there, but still, this girl was brilliant. Besides school and work for the department, she also taught aerobics, had a full time boy friend, socialized a great deal, and read 2 or 3 novels per week.
PS, your "Test question" appears pointless since the terms 'near' and 'far' are subjective.
Arthur
No he didn't fail Biology, but you need to dwell on "reading comprehension" here.
(He is referring to two different people.)
But on the "Test question" remark, you are correct -- they are subjective. Nice insight.
IN MY FATHER'S HOUSE ARE MANY DWELLING PLACES
IF IT WERE NOT SO I WOULD HAVE TOLD YOU
FOR I GO TO PREPARE A PLACE FOR YOU
QUOTE ( (metamars @ May 13 2007+ 04:36 PM))
You remind of a student I tutored when I was in graduate school, who seemed unable to solve the simplest of problems. It finally occurred to me that his brain did not seem to have a grasp of relative distance. So, I asked him, "If point A is far from point B, but point C is near point B, what can we say about the relationship between points A and C?"
He failed that test.
Before you make yet another of your not-so-omniscient remarks about the quality of this school, be aware that a fellow graduate student could easily read and comprehend 200 or 300 pages of linear algebra at a clip. Linear algebra may be the simplest abstract (proofs and theorems) course out there, but still, this girl was brilliant. Besides school and work for the department, she also taught aerobics, had a full time boy friend, socialized a great deal, and read 2 or 3 novels per week.
PS, your "Test question" appears pointless since the terms 'near' and 'far' are subjective.
Arthur
No he didn't fail Biology, but you need to dwell on "reading comprehension" here.
(He is referring to two different people.)
But on the "Test question" remark, you are correct -- they are subjective. Nice insight.
IN MY FATHER'S HOUSE ARE MANY DWELLING PLACES
IF IT WERE NOT SO I WOULD HAVE TOLD YOU
FOR I GO TO PREPARE A PLACE FOR YOU
QUOTE (quicknthedead+May 14 2007, 11:05 PM)
He is referring to two different people.
You're right, which makes the WHOLE post as pointless as his "test".
Arthur
You're right, which makes the WHOLE post as pointless as his "test".
Arthur
QUOTE (cerberus+May 14 2007, 11:05 PM)
What logical basis do you have for assuming, as NIST did, that debris directed asymmetrically from the plane impact that "failed partitions in front of core columns" automatically translates into the fire protection being dislodged ...etc...etc
I think the answer is simple. Statistically a lot of things at 9/11 were improbable; the product of probabilities is very low. But since it happened (we saw it didn’t we?) then you have to assume it happened; you have to come with a solution because of the end result and then your only conclusion is that it is dislodges in that way otherwise we would have no collapse. Btw If you make an equation (I always have to think about the Drake formula calculating the chance of existence of intelligent life elsewhere) for all events at 9/11 and take the product of the individual chances you get a very very low probability.
I think the answer is simple. Statistically a lot of things at 9/11 were improbable; the product of probabilities is very low. But since it happened (we saw it didn’t we?) then you have to assume it happened; you have to come with a solution because of the end result and then your only conclusion is that it is dislodges in that way otherwise we would have no collapse. Btw If you make an equation (I always have to think about the Drake formula calculating the chance of existence of intelligent life elsewhere) for all events at 9/11 and take the product of the individual chances you get a very very low probability.
QUOTE (David B. Benson+May 14 2007, 10:22 PM)
Try this: Cross-sectional area is denoted by A; length is denoted by L, density by d. The effective mass is
m = d(AL)/3
The spring stiffness is
k = E(A/L).
Consider the ratio m/k used to determine the period of the mass-spring system:
m/k = (1/3)(d/E)(A/A)L^2 = (1/3)(d/E)L^2
which does not depend upon the cross-section area A. We conclude that the period of an extended mass-spring system is independent of the cross-sectional area anywhere along the length.
Seem correct to you?
No, it does not seem correct. I don't think this formula for the spring stiffness can be applied to get the period in the case where the linear density (dA) varies. This is because k will vary for different linear segments of the spring but the period formula was derived assuming k not to vary, right?
(Edited to add: stiffness isn't additive the way effective mass is.)
m = d(AL)/3
The spring stiffness is
k = E(A/L).
Consider the ratio m/k used to determine the period of the mass-spring system:
m/k = (1/3)(d/E)(A/A)L^2 = (1/3)(d/E)L^2
which does not depend upon the cross-section area A. We conclude that the period of an extended mass-spring system is independent of the cross-sectional area anywhere along the length.
Seem correct to you?
No, it does not seem correct. I don't think this formula for the spring stiffness can be applied to get the period in the case where the linear density (dA) varies. This is because k will vary for different linear segments of the spring but the period formula was derived assuming k not to vary, right?
(Edited to add: stiffness isn't additive the way effective mass is.)
I'm not sure what you want to do but could you not divide the spring in infinitesimal small springs and integrate it ?
QUOTE (cerberus+May 14 2007, 11:05 PM)
Those tests demonstrated that the SFRM was dislodged from flat surfaces only if it was directed in a very symmetrical fashion from a narrow range of angles of 0-40 degrees, and for the tests involving the small, round steel bars, the SFRM was only dislodged by direct impact with the shotgun pellets, leaving the SFRM immediately outside of the small blast pattern in place. This is a very narrow range of parameters required for the dislodging of the fire protection. Also, there are no assumptions that can be made based on these tests in regards to core columns protected by gypsum wallboard or a combination of gypsum wallboard and SFRM.
Since when is 80 out of 180 degrees a narrow range? It's nearly half of all possible angles of impact for the flat surfaces. In the case of the bar joists, damage will occur at any angle. The test debris energy was modeled to simulate the actual debris energy, not the energy that was required to remove the SFRM. It only takes a few psi tensile pull to separate SFRM. Only about 3% of the kinetic energy of the impact was lost penetrating the exterior walls, so there was ample momentum transfer to the interior elements to generate enough ballistic material in all directions to damage the SFRM
QUOTE
QUOTE (->
| QUOTE |
| Your continual reference to the 6,000 sq meter area has NO BASIS in what NIST did. Sure it does, if you add up the surface area of the structural steel, using NIST's own assumption, in the areas depicted in their diagrams indicating dislodged fire protection. |
That 6,000 meter area is the area containing the fire proofed members, not the surface area of the members themselves. The effected members surface area would have been a fraction of that number.
QUOTE
This certainly doesn't change the total amount of kinetic energy available from the impact. So instead of all of the kinetic energy being consumed in the breaking of columns and the crushing of floors, a relatively small amount by comparison is allocated to pushing around and crushing cubicles and file cabinets.
NIST in their debris impact test assumed that about 1/3 of the total kinetic energy was available for debris movement. QUOTE (->
| QUOTE |
| This certainly doesn't change the total amount of kinetic energy available from the impact. So instead of all of the kinetic energy being consumed in the breaking of columns and the crushing of floors, a relatively small amount by comparison is allocated to pushing around and crushing cubicles and file cabinets. |
NIST in their debris impact test assumed that about 1/3 of the total kinetic energy was available for debris movement.
This brings up a good question though. How did the impact debris strip the fire protection from the columns and floor trusses in the areas of concern and leave the workstations in place in the same areas to be utilized as fuel?..
This brings up a good question though. How did the impact debris strip the fire protection from the columns and floor trusses in the areas of concern and leave the workstations in place in the same areas to be utilized as fuel?..
While flammable debris may not have been evenly distributed, the hot gases produced by their fires were free to circulate to areas of low fuel.
Just saw a post about a Steven E Jones paper at JREF.
http://journalof911studies.com/volume/2007...11SciMethod.pdf
He refers to the recently discussed Kuttler paper, ignore that, but his wtc7 part is excellent.
As scientists we have to include that evidence and not just limit ourselves to floor 8 to 46 as NIST solicitation requires.
I always thought it couldn't be more crazy than it already was, my jaws dropped on my desk... this can't be true of course
http://journalof911studies.com/volume/2007...11SciMethod.pdf
He refers to the recently discussed Kuttler paper, ignore that, but his wtc7 part is excellent.
As scientists we have to include that evidence and not just limit ourselves to floor 8 to 46 as NIST solicitation requires.
I always thought it couldn't be more crazy than it already was, my jaws dropped on my desk... this can't be true of course
QUOTE (NIST FAQ+)
Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
Actually video evidence is quite reliable. You know the distance by knowing the height. Then it's just a matter of timing how long it took for the top to reach the bottom. There are videos that show the entire collapse (I have seen one) and you can tell very distinctly when it begins to collapse (it happens out of the blue rather than gradual showing signs of collapse before it did). Between knowing the distance and time to travel the distance you can find out that the top of the building fell in a near free fall. It actually fell equivalently to demo'ed buildings.
Yes, video evidence can be reliable, but there are NO videos that show the entire collapse, as in all of them the last part of the collaspe can not be seen "due to obstruction of view caused by debris clouds."
They didn't fall at free fall speed, watch the videos and you can see the material that is falling outside the towers clearly falling much faster than the towers.
The collapse does NOT happen out of the blue, a long truss side of both towers SLOWLY bows in over time prior to the collapse.
No, the beams at the bottom were NOT the same beams at the top. Beams were 3 stories in height and got smaller as they went up and the loads decreased.
They both tilted towards the side where the fire weakened the structure the most. The impact was severe but ultimately the fire did more structural damage. The second tower received MORE damage to the core because the plane hit on the "short floor" side, thus arriving at the core with more kinetic energy remaining. Worse, the damage was more asymetrical, thus after the impact the loads were more heavily distributed to the DAMAGED side and that was the same side that the fires were mainly on. This assault on mainly one side of the building caused not only a faster collapse but a more dramatic tilt when the tower failed.
The energy from the ~2/3rds of the plane fuel that burned inside the towers was a small fraction of the energy released from the fuel from the building contents.
The fuel from the plane was responsible mainly for setting simultaneous widespread multifloor fires, the effect of which is worse than your typical floor to floor office fire as columns were heated over multiple floors at one time and floor trusses were heated from both top and bottom at the same time.
Please read NIST NCSTAR The Final Report.
Arthur
No, the beams at the bottom were NOT the same beams at the top. Beams were 3 stories in height and got smaller as they went up and the loads decreased.
Are you talking about columns or beams?
QUOTE (Precursor562+May 14 2007, 08:32 PM)
Actually video evidence is quite reliable. You know the distance by knowing the height. Then it's just a matter of timing how long it took for the top to reach the bottom. There are videos that show the entire collapse (I have seen one) and you can tell very distinctly when it begins to collapse (it happens out of the blue rather than gradual showing signs of collapse before it did). Between knowing the distance and time to travel the distance you can find out that the top of the building fell in a near free fall. It actually fell equivalently to demo'ed buildings.
Yes, video evidence can be reliable, but there are NO videos that show the entire collapse, as in all of them the last part of the collaspe can not be seen "due to obstruction of view caused by debris clouds."
They didn't fall at free fall speed, watch the videos and you can see the material that is falling outside the towers clearly falling much faster than the towers.
The collapse does NOT happen out of the blue, a long truss side of both towers SLOWLY bows in over time prior to the collapse.
QUOTE
The same beams found at the bottom that supported the entire building extended all the way up. So if a section of beam is strong enough to support the entire building it will most certainly be strong enough to support 30% of the total weight. It would take a lot of heat and burning time to weaken the steel and even if it did then it would topple over toward the weaker side which it didn't.
The temperature of the fires were not hot enough and did not burn long enough even if they were hot enough. The second tower received less damage and almost all the fuel of the plane (hottest burning substance there) burned up in one big fireball outside the adjacent side since the plane only clipped the corner.
The temperature of the fires were not hot enough and did not burn long enough even if they were hot enough. The second tower received less damage and almost all the fuel of the plane (hottest burning substance there) burned up in one big fireball outside the adjacent side since the plane only clipped the corner.
No, the beams at the bottom were NOT the same beams at the top. Beams were 3 stories in height and got smaller as they went up and the loads decreased.
They both tilted towards the side where the fire weakened the structure the most. The impact was severe but ultimately the fire did more structural damage. The second tower received MORE damage to the core because the plane hit on the "short floor" side, thus arriving at the core with more kinetic energy remaining. Worse, the damage was more asymetrical, thus after the impact the loads were more heavily distributed to the DAMAGED side and that was the same side that the fires were mainly on. This assault on mainly one side of the building caused not only a faster collapse but a more dramatic tilt when the tower failed.
The energy from the ~2/3rds of the plane fuel that burned inside the towers was a small fraction of the energy released from the fuel from the building contents.
The fuel from the plane was responsible mainly for setting simultaneous widespread multifloor fires, the effect of which is worse than your typical floor to floor office fire as columns were heated over multiple floors at one time and floor trusses were heated from both top and bottom at the same time.
Please read NIST NCSTAR The Final Report.
Arthur
QUOTE (einsteen+May 15 2007, 07:23 AM)
Just saw a post about a Steven E Jones paper at JREF.
http://journalof911studies.com/volume/2007...11SciMethod.pdf
He refers to the recently discussed Kuttler paper, ignore that, but his wtc7 part is excellent.
As scientists we have to include that evidence and not just limit ourselves to floor 8 to 46 as NIST solicitation requires.
I always thought it couldn't be more crazy than it already was, my jaws dropped on my desk... this can't be true of course
Of course it ISN'T true, and it took only a few minutes to prove that Jones is wrong.
See http://wtc.nist.gov/solicitations/
NIST does a lot of its own work and contracts out other parts.
For ARA there are MULTIPLE CONTRACTS which include ALL the floors.
Look at the contracts in DETAIL:
ARA will conduct analyses, in collaboration with NIST, to determine the location and cause of the initiating event (i.e., the first component or group of components that failed) that led to global collapse of WTC 7. The analyses will determine the series of component and subsystem failures subsequent to the initiating event that led to global collapse that are consistent with observations from video and photographic records and other evidence. NIST will conduct all fire analysis of the building and analysis of the structural response to fires in-house and supply ARA initiating event data based on the in-house analyses.
ARA will conduct nonlinear dynamic collapse analyses using LS-DYNA that include analyses of detailed full floor models and global models. The detailed floor analyses will determine likely modes of failure for Floors 8 to 46 due to failure of one or more supporting columns (at one or more locations), and aid the development of a more coarse model for use in the global analyses that captures essential behaviors and failure mechanisms. Two types of global analyses will be conducted. Sensitivity studies will be conducted to determine the response of WTC 7 to various scenarios of initiating events. Final analyses will support the determination of the location and cause of the initiating event, by incorporating data from NIST for simulating the initiating event, as well as the location and cause of subsequent failures that led to global collapse.
Contract 2
ARA (1) shall conduct analyses of impact damage and fire effects to provide candidate initiating events which may lead to structural failures and global collapse, and (2) shall determine if there is any scenario of a hypothetical blast event or events that could have occurred in WTC 7 on September 11, 2001.
The specific tasks that ARA will perform with SGH (task 1) and LGI (task 2) include:
1. Identify and analyze hypothetical blast scenarios in three phases, with the results from each phase being used to decide if the analyses in the next phase is required:
> Identify hypothetical blast scenarios, using analysis and/or experience, to determine conditions that would fail specified column sections by direct attachment of explosive materials.
> Analyze the overpressure produced by the blast load and determine if the overpressure would have failed windows in WTC 7.
> Determine if the overpressure would result in sound levels transmitted through intact WTC 7 windows that could be heard outside the building.
2. Conduct the following analyses using a three-dimensional ANSYS model (provided by NIST) of the lower 16 floors of WTC 7:
> Review the ANSYS model provided by NIST for conducting structural analysis of damage to components and the effect of time-varying temperatures. Identify possible revisions/improvements to the ANSYS model that may improve efficiency, accuracy and/or capture of critical failure modes.
> Work with NIST staff to incorporate agreed upon changes to the ANSYS model.
> Determine the structural response of WTC 7 for up to six scenarios of structural damage from debris impact and temperature histories provided by NIST. NIST will conduct analyses of other scenarios in parallel. Work with NIST to identify the structural response and failure modes for each analysis.
Arthur
http://journalof911studies.com/volume/2007...11SciMethod.pdf
He refers to the recently discussed Kuttler paper, ignore that, but his wtc7 part is excellent.
As scientists we have to include that evidence and not just limit ourselves to floor 8 to 46 as NIST solicitation requires.
I always thought it couldn't be more crazy than it already was, my jaws dropped on my desk... this can't be true of course
Of course it ISN'T true, and it took only a few minutes to prove that Jones is wrong.
See http://wtc.nist.gov/solicitations/
NIST does a lot of its own work and contracts out other parts.
For ARA there are MULTIPLE CONTRACTS which include ALL the floors.
Look at the contracts in DETAIL:
ARA will conduct analyses, in collaboration with NIST, to determine the location and cause of the initiating event (i.e., the first component or group of components that failed) that led to global collapse of WTC 7. The analyses will determine the series of component and subsystem failures subsequent to the initiating event that led to global collapse that are consistent with observations from video and photographic records and other evidence. NIST will conduct all fire analysis of the building and analysis of the structural response to fires in-house and supply ARA initiating event data based on the in-house analyses.
ARA will conduct nonlinear dynamic collapse analyses using LS-DYNA that include analyses of detailed full floor models and global models. The detailed floor analyses will determine likely modes of failure for Floors 8 to 46 due to failure of one or more supporting columns (at one or more locations), and aid the development of a more coarse model for use in the global analyses that captures essential behaviors and failure mechanisms. Two types of global analyses will be conducted. Sensitivity studies will be conducted to determine the response of WTC 7 to various scenarios of initiating events. Final analyses will support the determination of the location and cause of the initiating event, by incorporating data from NIST for simulating the initiating event, as well as the location and cause of subsequent failures that led to global collapse.
Contract 2
ARA (1) shall conduct analyses of impact damage and fire effects to provide candidate initiating events which may lead to structural failures and global collapse, and (2) shall determine if there is any scenario of a hypothetical blast event or events that could have occurred in WTC 7 on September 11, 2001.
The specific tasks that ARA will perform with SGH (task 1) and LGI (task 2) include:
1. Identify and analyze hypothetical blast scenarios in three phases, with the results from each phase being used to decide if the analyses in the next phase is required:
> Identify hypothetical blast scenarios, using analysis and/or experience, to determine conditions that would fail specified column sections by direct attachment of explosive materials.
> Analyze the overpressure produced by the blast load and determine if the overpressure would have failed windows in WTC 7.
> Determine if the overpressure would result in sound levels transmitted through intact WTC 7 windows that could be heard outside the building.
2. Conduct the following analyses using a three-dimensional ANSYS model (provided by NIST) of the lower 16 floors of WTC 7:
> Review the ANSYS model provided by NIST for conducting structural analysis of damage to components and the effect of time-varying temperatures. Identify possible revisions/improvements to the ANSYS model that may improve efficiency, accuracy and/or capture of critical failure modes.
> Work with NIST staff to incorporate agreed upon changes to the ANSYS model.
> Determine the structural response of WTC 7 for up to six scenarios of structural damage from debris impact and temperature histories provided by NIST. NIST will conduct analyses of other scenarios in parallel. Work with NIST to identify the structural response and failure modes for each analysis.
Arthur
Does that mean he is a forger ? 
QUOTE (adoucette+May 15 2007, 07:34 AM)
No, the beams at the bottom were NOT the same beams at the top. Beams were 3 stories in height and got smaller as they went up and the loads decreased.
Are you talking about columns or beams?
quicknthedead
Liar-for-Jesus
Grumpy
QUOTE
Oh, and you are wrong again on all accounts.
Liar-for-Jesus
Grumpy
QUOTE (Palpatane+May 15 2007, 09:55 AM)
Are you talking about columns or beams?
Actually they are columns, but I used the same terms he did
Arthur
Actually they are columns, but I used the same terms he did
QUOTE
The same beams found at the bottom that supported the entire building extended all the way up.
so as to not confuse. Arthur
QUOTE (einsteen+May 15 2007, 09:53 AM)
Does that mean he is a forger ?
Forger?
No, but clearly both HE and Kuttler do only CURSORY checking of facts, or IMHO, are ATTEMPTING to deceive. Problem is they aren't very good at EITHER.
This from Jone's paper:
Accordingly, several careful studies were performed regarding the collapse of WTC 7.17 I wish to call attention to this footnote in a paper by Professor Kenneth Kuttler:
“any further analysis of WTC7 should include all floors (not just “floors 8 to 46”) and conservation of momentum considerations.” 18
Now why would he say this about including all the floors in further analysis work, and not “just floors 8 to 46”? Dr. Kuttler’s paper points to a NIST solicitation. After the NIST final report on WTC7 was already long overdue, they solicited proposals for someone else to study the collapse of building 7. The grant went to ARA in New Mexico, and here is the solicitation that went out from NIST regarding the collapse of Building 7:
“Create detailed floor analyses to determine likely modes of failure for Floors 8 to 46 due to failure of one or more supporting columns (at one or more locations) at the World Trade Center Building Seven.” 19
We want to understand the collapse of this building, yet NIST is asking whoever accepts the contract to put blinders on and only consider “floors 8 to 46.” That, to me, is not a very scientific way to proceed. As a scientist, what does this make me want to do? Of course I want to know, “what happened below floor 8? Why should I not consider what happened below floor 8, or above floor 46?”
Why would someone like Jones do this?
Well the same reason why someone would put POLITICS into a scientific paper.
Maybe this is more about Jone's POLITICAL views than his scientific ones?
Forger?
No, but clearly both HE and Kuttler do only CURSORY checking of facts, or IMHO, are ATTEMPTING to deceive. Problem is they aren't very good at EITHER.
This from Jone's paper:
Accordingly, several careful studies were performed regarding the collapse of WTC 7.17 I wish to call attention to this footnote in a paper by Professor Kenneth Kuttler:
“any further analysis of WTC7 should include all floors (not just “floors 8 to 46”) and conservation of momentum considerations.” 18
Now why would he say this about including all the floors in further analysis work, and not “just floors 8 to 46”? Dr. Kuttler’s paper points to a NIST solicitation. After the NIST final report on WTC7 was already long overdue, they solicited proposals for someone else to study the collapse of building 7. The grant went to ARA in New Mexico, and here is the solicitation that went out from NIST regarding the collapse of Building 7:
“Create detailed floor analyses to determine likely modes of failure for Floors 8 to 46 due to failure of one or more supporting columns (at one or more locations) at the World Trade Center Building Seven.” 19
We want to understand the collapse of this building, yet NIST is asking whoever accepts the contract to put blinders on and only consider “floors 8 to 46.” That, to me, is not a very scientific way to proceed. As a scientist, what does this make me want to do? Of course I want to know, “what happened below floor 8? Why should I not consider what happened below floor 8, or above floor 46?”
Why would someone like Jones do this?
Well the same reason why someone would put POLITICS into a scientific paper.
Maybe this is more about Jone's POLITICAL views than his scientific ones?
QUOTE (BYU Jones+)
many responsible citizens of the world demand an end to the 9/11 wars.
...
I’m hoping that with the change that we just had in this election (with Democrats controlling both houses of Congress) that there will be some opening up and we’ll be able to look at ALL the floors in Building 7 and not just floors 8 to 46. That would be one great outcome of this election, freeing up science!
Arthur
...
I’m hoping that with the change that we just had in this election (with Democrats controlling both houses of Congress) that there will be some opening up and we’ll be able to look at ALL the floors in Building 7 and not just floors 8 to 46. That would be one great outcome of this election, freeing up science!
Arthur
I don't suppose it occured to that nitwit, Jones, that the building structure was significantly different from 8 on up, did it?
QUOTE (Capracus+May 15 2007, 11:17 AM)
Only about 3% of the kinetic energy of the impact was lost penetrating the exterior walls
A numerical simulation of the aircraft impact into the exterior columns of the World Trade Center (WTC) was done using LS-DYNA. For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams. Actual masses, material properties and dimensions of the Boeing 767 aircraft and the exterior columns of the WTC were used in this analysis. It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns. The minimum impact velocity of the aircraft to just penetrate the exterior columns would be 130 m/s. It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
Mohammed R. Karim and Michelle S. Hoo Fatt
A numerical simulation of the aircraft impact into the exterior columns of the World Trade Center (WTC) was done using LS-DYNA. For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams. Actual masses, material properties and dimensions of the Boeing 767 aircraft and the exterior columns of the WTC were used in this analysis. It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns. The minimum impact velocity of the aircraft to just penetrate the exterior columns would be 130 m/s. It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
Mohammed R. Karim and Michelle S. Hoo Fatt
einsteen
http://img326.imageshack.us/img326/2438/wtc7vj.png
This is not a perfect illustration(the external frames collapse first, then the overloaded core snaps, then the floors start "bagelling(DBB)) but it illustrates fairly well the sequence.
Grumpy
http://img326.imageshack.us/img326/2438/wtc7vj.png
This is not a perfect illustration(the external frames collapse first, then the overloaded core snaps, then the floors start "bagelling(DBB)) but it illustrates fairly well the sequence.
Grumpy
QUOTE (Pierre-Normand+May 15 2007, 09:56 AM)
This is because k will vary for different linear segments of the spring ...
Yes, but try it this way. In the linear pressure wave equation the velocity v is given by
v = sqrt(E/d)
where E is Young's modulus and d is the density. That's what I get, up to the effective mass correction factor, doing it via sqrt(m/k).
This is, in effect, eistein's suggestion of integrating...
But I'll do some further checking.
Edited to add: Looking a acoustic waves in conical cylinders one finds that the solutions are expressed in terms of
f(t-kx)/x + g(t+kx)/x
for arbitrary (twice differentiable) functions determined by the boundary conditions, k being the wave number. So harmonic solutions are typically those best expressed in spherical coordinates, not something I ever studied in any depth.
However, the general point remains. Eventually the pressure wave reflects off the bottom and re-expansion begins. Checking a page on Pipes and Harmonics shows that the fundamental period for both the right cylinder and the conical cylinder is the same.
So the prior estimates for the period are correct, it seems, for sloping columns of circular cross section. I doubt anything substantial changes using other cross section shapes, but I'll certainly listen to what anybody cares to add...
Yes, but try it this way. In the linear pressure wave equation the velocity v is given by
v = sqrt(E/d)
where E is Young's modulus and d is the density. That's what I get, up to the effective mass correction factor, doing it via sqrt(m/k).
This is, in effect, eistein's suggestion of integrating...
But I'll do some further checking.
Edited to add: Looking a acoustic waves in conical cylinders one finds that the solutions are expressed in terms of
f(t-kx)/x + g(t+kx)/x
for arbitrary (twice differentiable) functions determined by the boundary conditions, k being the wave number. So harmonic solutions are typically those best expressed in spherical coordinates, not something I ever studied in any depth.
However, the general point remains. Eventually the pressure wave reflects off the bottom and re-expansion begins. Checking a page on Pipes and Harmonics shows that the fundamental period for both the right cylinder and the conical cylinder is the same.
So the prior estimates for the period are correct, it seems, for sloping columns of circular cross section. I doubt anything substantial changes using other cross section shapes, but I'll certainly listen to what anybody cares to add...
Daru
Leaving ~54% of the kenetic energy and ~66% of the thermal and overpressure energy to damage core columns, fireproofing, floor contents and start instantly huge multifloor, widespread fires.
What is your point???
Grumpy
QUOTE
It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns.
Leaving ~54% of the kenetic energy and ~66% of the thermal and overpressure energy to damage core columns, fireproofing, floor contents and start instantly huge multifloor, widespread fires.
What is your point???
Grumpy
Correction: not sloping columns but tapered columns, i.e., sections of a right cone.
QUOTE (Daru+May 15 2007, 01:03 PM)
A numerical simulation of the aircraft impact into the exterior columns of the World Trade Center (WTC) was done using LS-DYNA. For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams. Actual masses, material properties and dimensions of the Boeing 767 aircraft and the exterior columns of the WTC were used in this analysis. It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns. The minimum impact velocity of the aircraft to just penetrate the exterior columns would be 130 m/s. It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams.
Not sure the point of this study, since NIST did a MUCH more detailed analysis.
Arthur
For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams.
Not sure the point of this study, since NIST did a MUCH more detailed analysis.
Arthur
QUOTE (Grumpy+May 15 2007, 06:10 PM)
What is your point???
Grumpy
I have many many many point.
In the article they say:
"Fig. 7 shows the failure process at different time steps when the
aircraft impacts the building at the top speed (240 m/ s) with a
full fuel tank and the exterior columns have the original column
thickness of 9.5 mm. It is observed that all columns fail and the
aircraft penetrates through the exterior wall. It is also found that
about 46% of the total initial kinetic energy of the aircraft is
absorbed in damaging the exterior columns and the aircraft. The
residual impact velocity of the aircraft after the penetration is
171 m/ s."
First, the exterior columns alone simply eat up the kinetic energy. After that the impact velocity is only 171 m/s to crush and cut concrete floors steel trusses and inner core columns... let alone the sfrm on many floors!!
Second, they assume that the column thickness is 9.5 mm (that is, the steel plate. Not all the hollow box column)
I think it was much thicker. Maybe up to 20 mm. (based on the photos from nist of the exterior columns from the impact zoone)
Grumpy
I have many many many point.
In the article they say:
"Fig. 7 shows the failure process at different time steps when the
aircraft impacts the building at the top speed (240 m/ s) with a
full fuel tank and the exterior columns have the original column
thickness of 9.5 mm. It is observed that all columns fail and the
aircraft penetrates through the exterior wall. It is also found that
about 46% of the total initial kinetic energy of the aircraft is
absorbed in damaging the exterior columns and the aircraft. The
residual impact velocity of the aircraft after the penetration is
171 m/ s."
First, the exterior columns alone simply eat up the kinetic energy. After that the impact velocity is only 171 m/s to crush and cut concrete floors steel trusses and inner core columns... let alone the sfrm on many floors!!
Second, they assume that the column thickness is 9.5 mm (that is, the steel plate. Not all the hollow box column)
I think it was much thicker. Maybe up to 20 mm. (based on the photos from nist of the exterior columns from the impact zoone)
Other examples of Craig t. Furlongs Lyin-for-Jesus
Evidence??? Craig don't need no stinkin' evidence, he just knows(did Jesus tell him?).
Evidence??? Craig don't need no stinkin' evidence, he just knows(did Jesus tell him?).
It was not hit by an airplane…
Well, DUH!!! It was only hit by hundreds of tons of steel from WTC1.
HORSE POO!!!
HORSE POO!!!
It was practically a government facility (look at the tenant list)…
So???
The first true statement in his whole diatribe, will it cause him to think about the impossibility of doing this work unobserved???
The first true statement in his whole diatribe, will it cause him to think about the impossibility of doing this work unobserved???
Why has the US controlled Media not covered this glaring, critical question AT ALL? (Answer: they want to keep their paychecks and food on the table.)
Why has the US Government and the whitewashing, disreputable 9/11 Commission basically ignored this entire matter by stating they don’t know? (And you can’t get them to talk about it, either.)
The perpetrators of 9/11 were not those whom the US Government would have you believe. No, the bad guys were the US Government. They’re the ones doing the cover up; after all, the ones usually responsible are the ones doing the cover up.
They had plenty of motive too, but that’s another topic.
Their OP didn’t run too well, though, with way too many unanswered questions the result.
Nope, no thinking will be done when Craig is in charge, notice his switch of topics here. If the evidence shows your fantasy to be impossible, ignore it(or continue to INSIST it is real, like firetruck reflections, eh, Craig???)
What is there to refute, all I see is your claims and lies, Craig. And the rantings of a paranoid nitwit!!!
Grumpy
QUOTE
The Achille’s Heel by Craig T. Furlong
This is not rocket science. ALL of 9/11 can be synthesized down to one thing: WTC7. (Please do not misunderstand, I do not discount the overwhelming preponderance of other damning evidence that implicates the US Government; I simply state it is not needed “to get the ball rolling” and finally bring down their house of cards.)
WTC7 is their Achille’s Heel. A quick view of any one of the many videos available on the internet exposes a glaring, critical question to all of the Government’s explanations of what happened that day. There IS something rotten in Denmark.
WTC7.
WTC7 collapsed falling into its own footprint with all the characteristics of a controlled demolition. That’s because it WAS a CLASSIC, CONTROLLED DEMOLITION.
Anyone who says otherwise is either (1) ignorant, or
(2) got his/her head so deep in the sand they are basically those of choice (1), or
(3) he/she is a coward to the truth [aka cognitive dissonance], or finally
(4) he/she is in league with the bad guys. (These are the only possible, logical choices.)
It was a controlled demolition…
This is not rocket science. ALL of 9/11 can be synthesized down to one thing: WTC7. (Please do not misunderstand, I do not discount the overwhelming preponderance of other damning evidence that implicates the US Government; I simply state it is not needed “to get the ball rolling” and finally bring down their house of cards.)
WTC7 is their Achille’s Heel. A quick view of any one of the many videos available on the internet exposes a glaring, critical question to all of the Government’s explanations of what happened that day. There IS something rotten in Denmark.
WTC7.
WTC7 collapsed falling into its own footprint with all the characteristics of a controlled demolition. That’s because it WAS a CLASSIC, CONTROLLED DEMOLITION.
Anyone who says otherwise is either (1) ignorant, or
(2) got his/her head so deep in the sand they are basically those of choice (1), or
(3) he/she is a coward to the truth [aka cognitive dissonance], or finally
(4) he/she is in league with the bad guys. (These are the only possible, logical choices.)
It was a controlled demolition…
Evidence??? Craig don't need no stinkin' evidence, he just knows(did Jesus tell him?).
QUOTE (->
| QUOTE |
| The Achille’s Heel by Craig T. Furlong This is not rocket science. ALL of 9/11 can be synthesized down to one thing: WTC7. (Please do not misunderstand, I do not discount the overwhelming preponderance of other damning evidence that implicates the US Government; I simply state it is not needed “to get the ball rolling” and finally bring down their house of cards.) WTC7 is their Achille’s Heel. A quick view of any one of the many videos available on the internet exposes a glaring, critical question to all of the Government’s explanations of what happened that day. There IS something rotten in Denmark. WTC7. WTC7 collapsed falling into its own footprint with all the characteristics of a controlled demolition. That’s because it WAS a CLASSIC, CONTROLLED DEMOLITION. Anyone who says otherwise is either (1) ignorant, or (2) got his/her head so deep in the sand they are basically those of choice (1), or (3) he/she is a coward to the truth [aka cognitive dissonance], or finally (4) he/she is in league with the bad guys. (These are the only possible, logical choices.) It was a controlled demolition… |
Evidence??? Craig don't need no stinkin' evidence, he just knows(did Jesus tell him?).
It was not hit by an airplane…
Well, DUH!!! It was only hit by hundreds of tons of steel from WTC1.
QUOTE
Fire has never in history been the cause for a large-scale building to collapse (according to the Government, however, this has happened three times; unfortunately, they are referring to September 11, 2001)…
HORSE POO!!!
QUOTE (->
| QUOTE |
| Fire has never in history been the cause for a large-scale building to collapse (according to the Government, however, this has happened three times; unfortunately, they are referring to September 11, 2001)… |
HORSE POO!!!
It was practically a government facility (look at the tenant list)…
So???
QUOTE
Prepping a building for a controlled demolition takes at least a minimum 2 weeks to prepare, often longer…
So, how did it implode that day via controlled demolition? I.e., how did they prep the building without being observed (box-cutter wielding jihadists could not have done this)?
So, how did it implode that day via controlled demolition? I.e., how did they prep the building without being observed (box-cutter wielding jihadists could not have done this)?
The first true statement in his whole diatribe, will it cause him to think about the impossibility of doing this work unobserved???
QUOTE (->
| QUOTE |
| Prepping a building for a controlled demolition takes at least a minimum 2 weeks to prepare, often longer… So, how did it implode that day via controlled demolition? I.e., how did they prep the building without being observed (box-cutter wielding jihadists could not have done this)? |
The first true statement in his whole diatribe, will it cause him to think about the impossibility of doing this work unobserved???
Why has the US controlled Media not covered this glaring, critical question AT ALL? (Answer: they want to keep their paychecks and food on the table.)
Why has the US Government and the whitewashing, disreputable 9/11 Commission basically ignored this entire matter by stating they don’t know? (And you can’t get them to talk about it, either.)
The perpetrators of 9/11 were not those whom the US Government would have you believe. No, the bad guys were the US Government. They’re the ones doing the cover up; after all, the ones usually responsible are the ones doing the cover up.
They had plenty of motive too, but that’s another topic.
Their OP didn’t run too well, though, with way too many unanswered questions the result.
Nope, no thinking will be done when Craig is in charge, notice his switch of topics here. If the evidence shows your fantasy to be impossible, ignore it(or continue to INSIST it is real, like firetruck reflections, eh, Craig???)
QUOTE
Especially glaring is their Achille’s Heel.
So, if you are honest with yourself, you can not refute this. And when most Americans finally see WTC7 come-tumbling-down, they will also understand.
Then we get these wicked people arrested and charged for murder and treason, and We The People take back America.
Do you like the sound of that?
So, if you are honest with yourself, you can not refute this. And when most Americans finally see WTC7 come-tumbling-down, they will also understand.
Then we get these wicked people arrested and charged for murder and treason, and We The People take back America.
Do you like the sound of that?
What is there to refute, all I see is your claims and lies, Craig. And the rantings of a paranoid nitwit!!!
Grumpy
Daru
46% of it, leaving 54% and the energy contained in the fuel.
46% of it, leaving 54% and the energy contained in the fuel.
After that the impact velocity is only 171 m/s to crush and cut concrete floors steel trusses and inner core columns... let alone the sfrm on many floors!!
And your point is??? Over half of a huge amount of energy is still a lot of energy!!!
They assume nothing, the steel schedules will give them specs for that steel, which is way more accurate than your "guess" base on photographs, I can assure you. All exterior columns appear IDENTICAL from the outside(which is what photos show), they varied according to the THICKNESS of the metal they were made from(which a photo will not accurately show).
Again, what's your point???
Grumpy
QUOTE
First, the exterior columns alone simply eat up the kinetic energy.
46% of it, leaving 54% and the energy contained in the fuel.
QUOTE (->
| QUOTE |
| First, the exterior columns alone simply eat up the kinetic energy. |
46% of it, leaving 54% and the energy contained in the fuel.
After that the impact velocity is only 171 m/s to crush and cut concrete floors steel trusses and inner core columns... let alone the sfrm on many floors!!
And your point is??? Over half of a huge amount of energy is still a lot of energy!!!
QUOTE
Second, they assume that the column thickness is 9.5 mm (that is, the steel plate. Not all the hollow box column)
I think it was much thicker. Maybe up to 20 mm. (based on the photos from nist of the exterior columns from the impact zoone)
I think it was much thicker. Maybe up to 20 mm. (based on the photos from nist of the exterior columns from the impact zoone)
They assume nothing, the steel schedules will give them specs for that steel, which is way more accurate than your "guess" base on photographs, I can assure you. All exterior columns appear IDENTICAL from the outside(which is what photos show), they varied according to the THICKNESS of the metal they were made from(which a photo will not accurately show).
Again, what's your point???
Grumpy
There is no energy to damage sfrm. Either they have to use it to cut floors and the massive inner core columns ... or the sfrm. It is not possible to have it both ways.
And no, the thickness of the wall is not known.
And no, the thickness of the wall is not known.
Does this look like a 9.5 mm ??
Just sorry... but there is clearly something wrong here.
It is possible to see pictures here:
killtown.911review.org/wtc-gallery.html
Just sorry... but there is clearly something wrong here.
It is possible to see pictures here:
killtown.911review.org/wtc-gallery.html
Daru
Not true, the steel schedules give very accurate thicknesses for every floor.
Not true, the steel schedules give very accurate thicknesses for every floor.
There is no energy to damage sfrm. Either they have to use it to cut floors and the massive inner core columns ... or the sfrm. It is not possible to have it both ways.
SFRM is very easy to strip off, taking just a few psi of overpressure. And there was a huge amount of energy available to do all the things NIST points out. What, do you think there were energy traffic cops directing the flow of energy during the collision and fireball??? "No, you can't strip this SFRM off, you have been allocated to break that beam!!!" The energy did what damage it happened to do until it was expended, a minor fraction of that available being enough to strip the estimated 800 SQM in the 6000SQM zone NIST estimated, the rest doing other damage.
And then the fires did the rest.
Grumpy
QUOTE
the thickness of the wall is not known.
Not true, the steel schedules give very accurate thicknesses for every floor.
QUOTE (->
| QUOTE |
| the thickness of the wall is not known. |
Not true, the steel schedules give very accurate thicknesses for every floor.
There is no energy to damage sfrm. Either they have to use it to cut floors and the massive inner core columns ... or the sfrm. It is not possible to have it both ways.
SFRM is very easy to strip off, taking just a few psi of overpressure. And there was a huge amount of energy available to do all the things NIST points out. What, do you think there were energy traffic cops directing the flow of energy during the collision and fireball??? "No, you can't strip this SFRM off, you have been allocated to break that beam!!!" The energy did what damage it happened to do until it was expended, a minor fraction of that available being enough to strip the estimated 800 SQM in the 6000SQM zone NIST estimated, the rest doing other damage.
And then the fires did the rest.
Grumpy
QUOTE (Grumpy+May 15 2007, 08:42 PM)
Daru
46% of it, leaving 56% and the energy contained in the fuel.
Grumpy
stellar math skills, 'genius' teacher.
46% of it, leaving 56% and the energy contained in the fuel.
Grumpy
stellar math skills, 'genius' teacher.
J.G. Fox & J. Mahanty, The Effective Mass of an Oscillating Spring, American J. Physics v. 38:1 (1970 Jan), 98--100, point out that the effective mass to be used varies from 4m/pi^2 ~ 0.405 m to m/3 as the supported mass M goes from 0 to infinity...
QUOTE (Daru+May 15 2007, 03:19 PM)
I have many many many point.
In the article they say:
"Fig. 7 shows the failure process at different time steps when the
aircraft impacts the building at the top speed (240 m/ s) with a
full fuel tank and the exterior columns have the original column
thickness of 9.5 mm. It is observed that all columns fail and the
aircraft penetrates through the exterior wall. It is also found that
about 46% of the total initial kinetic energy of the aircraft is
absorbed in damaging the exterior columns and the aircraft. The
residual impact velocity of the aircraft after the penetration is
171 m/ s."
First, the exterior columns alone simply eat up the kinetic energy. After that the impact velocity is only 171 m/s to crush and cut concrete floors steel trusses and inner core columns... let alone the sfrm on many floors!!
Second, they assume that the column thickness is 9.5 mm (that is, the steel plate. Not all the hollow box column)
I think it was much thicker. Maybe up to 20 mm. (based on the photos from nist of the exterior columns from the impact zoone)
Actually the damage to the Exterior was tremendous.
In WTC 2 for instance (the one hit lowest) over 40 of these Exterior columns over 6 floors were cut compared to 5 core columns cut and 4 severely damaged.
See NIST NCSTAR 1-2 Figure 7-36 and 7-43.
As to the Steel, Grumpy is correct, there is a schedule.
The MAJORITY of the columns in WTC 2 that were hit appear to be column type 124.
Column type 124 were made up of 4 plates of 2 different thicknesses.
See NIST NCSTAR 1-5G table B3
.0064 m front and back, and .0127 m for the sides. This sums to .0382 which averages to 0.095 m or 9.5 mm
Arthur
In the article they say:
"Fig. 7 shows the failure process at different time steps when the
aircraft impacts the building at the top speed (240 m/ s) with a
full fuel tank and the exterior columns have the original column
thickness of 9.5 mm. It is observed that all columns fail and the
aircraft penetrates through the exterior wall. It is also found that
about 46% of the total initial kinetic energy of the aircraft is
absorbed in damaging the exterior columns and the aircraft. The
residual impact velocity of the aircraft after the penetration is
171 m/ s."
First, the exterior columns alone simply eat up the kinetic energy. After that the impact velocity is only 171 m/s to crush and cut concrete floors steel trusses and inner core columns... let alone the sfrm on many floors!!
Second, they assume that the column thickness is 9.5 mm (that is, the steel plate. Not all the hollow box column)
I think it was much thicker. Maybe up to 20 mm. (based on the photos from nist of the exterior columns from the impact zoone)
Actually the damage to the Exterior was tremendous.
In WTC 2 for instance (the one hit lowest) over 40 of these Exterior columns over 6 floors were cut compared to 5 core columns cut and 4 severely damaged.
See NIST NCSTAR 1-2 Figure 7-36 and 7-43.
As to the Steel, Grumpy is correct, there is a schedule.
The MAJORITY of the columns in WTC 2 that were hit appear to be column type 124.
Column type 124 were made up of 4 plates of 2 different thicknesses.
See NIST NCSTAR 1-5G table B3
.0064 m front and back, and .0127 m for the sides. This sums to .0382 which averages to 0.095 m or 9.5 mm
Arthur
Tapered column mass-spring system --- Here is an approximate solution, enough to see that the tapering does not matter, provided the cross section geometry remains the same but for growing linearly larger when moving down. Take x increasing to mean moving down the column from the top. The cross sectional area is given by
A(x) = ax + b
for positive constants a and b with a small, a << b. Let y = dx be a very small increment > 0. Then
A(x+y) = A(x) + ay
so that the area over just the distance y is approximately A(x). Letting D be the effective density, D = 0.43 d, the effective mass over the distance y is
m = DA(x)y
and the spring stiffness is
k = EA(x)/y
so
m/k = (D/E) y^2
To obtain the period, we first need
Ky = sqrt((D/E)y^2) with K = sqrt(D/E), a constant. Now integrate Ky over the entire length L, with y = dx. We obtain
KL
as desired and the period is then
T = 2pi K L
which is the same as for a column of constant cross section. Is this ok?
If so, to obtain the compliance (reciprocal stiffness) integrate C(x) = dx/EA(x) to obtain
C = (1/aE)ln[A(L)/b]
Then, from Semitses & Hodges, the maximum deflection occurs at time T/2 and is
max = 2 C P
where P is the applied sudden load of infinite duration.
A(x) = ax + b
for positive constants a and b with a small, a << b. Let y = dx be a very small increment > 0. Then
A(x+y) = A(x) + ay
so that the area over just the distance y is approximately A(x). Letting D be the effective density, D = 0.43 d, the effective mass over the distance y is
m = DA(x)y
and the spring stiffness is
k = EA(x)/y
so
m/k = (D/E) y^2
To obtain the period, we first need
Ky = sqrt((D/E)y^2) with K = sqrt(D/E), a constant. Now integrate Ky over the entire length L, with y = dx. We obtain
KL
as desired and the period is then
T = 2pi K L
which is the same as for a column of constant cross section. Is this ok?
If so, to obtain the compliance (reciprocal stiffness) integrate C(x) = dx/EA(x) to obtain
C = (1/aE)ln[A(L)/b]
Then, from Semitses & Hodges, the maximum deflection occurs at time T/2 and is
max = 2 C P
where P is the applied sudden load of infinite duration.
Yes they say this or that but I dont buy it. It is obviously much thicker.
They say somewhere that the thickness was from 12.5 at the bottom to 7.5 at the top... and I dont buy it. If I look at the columns... the plates simply looked much thicker.
They are hiding something.
They say somewhere that the thickness was from 12.5 at the bottom to 7.5 at the top... and I dont buy it. If I look at the columns... the plates simply looked much thicker.
They are hiding something.
Daru
Paranoia will destroy ya'.
So now the builders of those buildings way back in the early seventies are in on it too??? Talk about foreknowledge!!!
The steel schedules are straight out of the building plans, they are FACTS no matter what they look like to you.
What is it with you CTers??? Another of you guys keeps thinking he sees the reflection of a firetruck in the back window of a BMW despite having been shown repeatedly that it is impossible to see ANY reflection in a back window sloped that steeply and the only thing there was the third brake light. Do you have to be blind as well as...Intellectually challenged to join that club???
Grumpy
QUOTE
Yes they say this or that but I dont buy it. It is obviously much thicker.
They say somewhere that the thickness was from 12.5 at the bottom to 7.5 at the top... and I dont buy it. If I look at the columns... the plates simply looked much thicker.
They are hiding something.
They say somewhere that the thickness was from 12.5 at the bottom to 7.5 at the top... and I dont buy it. If I look at the columns... the plates simply looked much thicker.
They are hiding something.
Paranoia will destroy ya'.
So now the builders of those buildings way back in the early seventies are in on it too??? Talk about foreknowledge!!!
The steel schedules are straight out of the building plans, they are FACTS no matter what they look like to you.
What is it with you CTers??? Another of you guys keeps thinking he sees the reflection of a firetruck in the back window of a BMW despite having been shown repeatedly that it is impossible to see ANY reflection in a back window sloped that steeply and the only thing there was the third brake light. Do you have to be blind as well as...Intellectually challenged to join that club???
Grumpy
That is exacly the point! Where is the orginal blueprint over the exterior columns ??
Ah, they are hiding it!!
But about it all... there are some picture of the exterior colums on the net. For example in nist report is picture which they say is from the impact zoone.
It is obviously much thicker than 9.5 mm. I can belive that each plate is 9.5 mm.
Ah, they are hiding it!!
But about it all... there are some picture of the exterior colums on the net. For example in nist report is picture which they say is from the impact zoone.
It is obviously much thicker than 9.5 mm. I can belive that each plate is 9.5 mm.
QUOTE (Daru+May 15 2007, 06:03 PM)
A numerical simulation of the aircraft impact into the exterior columns of the World Trade Center (WTC) was done using LS-DYNA. For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams. Actual masses, material properties and dimensions of the Boeing 767 aircraft and the exterior columns of the WTC were used in this analysis. It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns. The minimum impact velocity of the aircraft to just penetrate the exterior columns would be 130 m/s. It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
Mohammed R. Karim and Michelle S. Hoo Fatt
From Aircraft impact Damage:
http://www.box.net/shared/n7v5jguyef
Section 5.4, figure 18. The contribution of various members to the energy dissipated during the initial impact. North Tower, exterior column 4%. South Tower, exterior column 3%.
Mohammed R. Karim and Michelle S. Hoo Fatt
From Aircraft impact Damage:
http://www.box.net/shared/n7v5jguyef
Section 5.4, figure 18. The contribution of various members to the energy dissipated during the initial impact. North Tower, exterior column 4%. South Tower, exterior column 3%.
Daru
Can you please make up your mind!!!! GEEZE!!!
Can you please make up your mind!!!! GEEZE!!!
Ah, they are hiding it!!
Write to the Port Authority of NY,NJ and convince them you are a legitimate researcher and if they believe you be prepared to spend some thousands of dollars and you can have a set. Good luck with that.
They(PANY/NJ) aren't hiding it, but they aren't giving it away either. NIST does not have the right to release the intellectual property of others, though they included enough info in their report so that you could build your own Twin Towers. Saying they are hiding anything is first grade barn fertilizer(IE BS)
Please get a clue!!!
Grumpy
From Aircraft impact Damage:
http://www.box.net/shared/n7v5jguyef
Section 5.4, figure 18. The contribution of various members to the energy dissipated during the initial impact. North Tower, exterior column 4%. South Tower, exterior column 3%.
Yes. I know. MIT say this:
Table 3. Distribution of energy lost in the local damage of the TWC Towers. The energy is in the unit of MJ.
........................North ...................South
Airplane ..........586-23% ................586-25%
Exterior ...........103-4% .................122-3%
Floors .............1221-48% ...............1925-53%
Core columns ...630-25% ................1025-28%
Total................ 2540-100% .............3658-100%
So, why does Mohammed R. Karim and Michelle S. Hoo Fatt say 46% only to damage exterior columns.
Arthur
What exactly is so funny ??
They assume that the column thickness is 9.5... both plates.
I dont buy it... I can belive the inner and outer plate of the columns are 9.5 = about 20
And it is interesting that they also say:
It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
QUOTE
It is obviously much thicker than 9.5 mm. I can belive that each plate is 9.5 mm.
Can you please make up your mind!!!! GEEZE!!!
QUOTE (->
| QUOTE |
| It is obviously much thicker than 9.5 mm. I can belive that each plate is 9.5 mm. |
Can you please make up your mind!!!! GEEZE!!!
Ah, they are hiding it!!
Write to the Port Authority of NY,NJ and convince them you are a legitimate researcher and if they believe you be prepared to spend some thousands of dollars and you can have a set. Good luck with that.
They(PANY/NJ) aren't hiding it, but they aren't giving it away either. NIST does not have the right to release the intellectual property of others, though they included enough info in their report so that you could build your own Twin Towers. Saying they are hiding anything is first grade barn fertilizer(IE BS)
Please get a clue!!!
Grumpy
QUOTE (Daru+May 15 2007, 08:08 PM)
It is obviously much thicker than 9.5 mm. I can belive that each plate is 9.5 mm.
Arthur
Arthur
QUOTE (Capracus+May 16 2007, 01:17 AM)
From Aircraft impact Damage:
http://www.box.net/shared/n7v5jguyef
Section 5.4, figure 18. The contribution of various members to the energy dissipated during the initial impact. North Tower, exterior column 4%. South Tower, exterior column 3%.
Yes. I know. MIT say this:
Table 3. Distribution of energy lost in the local damage of the TWC Towers. The energy is in the unit of MJ.
........................North ...................South
Airplane ..........586-23% ................586-25%
Exterior ...........103-4% .................122-3%
Floors .............1221-48% ...............1925-53%
Core columns ...630-25% ................1025-28%
Total................ 2540-100% .............3658-100%
So, why does Mohammed R. Karim and Michelle S. Hoo Fatt say 46% only to damage exterior columns.
QUOTE (adoucette+May 16 2007, 01:28 AM)
Arthur
What exactly is so funny ??
They assume that the column thickness is 9.5... both plates.
I dont buy it... I can belive the inner and outer plate of the columns are 9.5 = about 20
And it is interesting that they also say:
It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
Daru
And yet the aircraft DID easily penetrate those wall, in the case of 2 parts made it through TWO walls. I think someone's math is WRONG and MIT's math is the more correct, wouldn't you???
Grumpy
QUOTE
What exactly is so funny ??
They assume that the column thickness is 9.5... both plates.
I dont buy it... I can belive the inner and outer plate of the columns are 9.5 = about 20
And it is interesting that they also say:
It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
They assume that the column thickness is 9.5... both plates.
I dont buy it... I can belive the inner and outer plate of the columns are 9.5 = about 20
And it is interesting that they also say:
It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
And yet the aircraft DID easily penetrate those wall, in the case of 2 parts made it through TWO walls. I think someone's math is WRONG and MIT's math is the more correct, wouldn't you???
Grumpy
QUOTE (Daru+May 15 2007, 08:42 PM)
What exactly is so funny ??
You
You keep stating what you can or can not BELIEVE.
But this is about SCIENCE, not BELIEFS.
They assume ALL 4 plates are 9.5 or 38 mm total.
They state that if ALL 4 plates were 20mm (or 80 total) that that would stop the plane.
But they appear to overstate the amount of energy taken up by the exterior columns.
My GUESS, since I haven't read their paper, is they may not have taken into account the fact that the columns were only BOLTED to their neighbors and almost HALF of the perimeter columns failed at their bolted connections on both towers.
The failure of the bolted connections would take SIGNIFICANTLY less energy than the failure of the actual columns.
Arthur
You
You keep stating what you can or can not BELIEVE.
But this is about SCIENCE, not BELIEFS.
They assume ALL 4 plates are 9.5 or 38 mm total.
They state that if ALL 4 plates were 20mm (or 80 total) that that would stop the plane.
But they appear to overstate the amount of energy taken up by the exterior columns.
My GUESS, since I haven't read their paper, is they may not have taken into account the fact that the columns were only BOLTED to their neighbors and almost HALF of the perimeter columns failed at their bolted connections on both towers.
The failure of the bolted connections would take SIGNIFICANTLY less energy than the failure of the actual columns.
Arthur
QUOTE (Grumpy+May 15 2007, 08:50 AM)
quicknthedead
Liar-for-Jesus
Grumpy
Your ad hominems are a sign of weakness.
On page 23 in Steven Jones' new paper, he writes about the microspheres discovered in the iron-rich dust:
http://journalof911studies.com/volume/2007...11SciMethod.pdf
The iron-rich component of the WTC dust sample was analyzed in some detail by scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (X-EDS). Using the scanning electron microscope, we found that much of the iron-rich dust was in fact composed of roughly spherical particles – microspheres. The presence of metallic microspheres implies that these metals were once molten, so that surface tension pulled the droplets into a roughly spherical shape. Then the molten droplets solidified in air, preserving the information that they were once molten in the spherical shape as well as chemical information.
Iron melts at 1538 oC, so the presence of these numerous iron-rich spheres implies a very high temperature. Too hot in fact for the fires in the WTC buildings since jet fuel (kerosene), paper and wood furniture – and other office materials – cannot reach the temperatures needed to melt iron or steel. (Remember the wood-burning stove…) Of course, elemental sulfur as found in thermate can lower the melting point of steel as discussed above.
As usual, we search for possible prosaic explanations for these metallic spherules in the WTC dust. The most obvious possible source is the melting of large quantities of steel in the buildings followed somehow by formation of tiny droplets of molten steel. As discussed above, however, steel melts at about 1538 oC (2800 oF) – and the temperatures in the buildings were no where near hot enough to melt steel, and certainly not in large quantities required for the amounts seen in the dust (and pouring out of the South Tower before collapse).
1538 degrees centigrade.
Dr. Frank Greening referred to these microspheres as "the great mystery of 9/11". Maybe a bit dramatic, but then again, maybe exactly where this is all headed.
LOOKING UNTO JESUS THE AUTHOR AND FINISHER OF OUR FAITH
WHO FOR THE JOY THAT WAS SET BEFORE HIM
ENDURED THE CROSS
DESPISING THE SHAME
AND IS SET DOWN AT THE RIGHT HAND OF THE THRONE OF GOD
Liar-for-Jesus
Grumpy
Your ad hominems are a sign of weakness.
On page 23 in Steven Jones' new paper, he writes about the microspheres discovered in the iron-rich dust:
http://journalof911studies.com/volume/2007...11SciMethod.pdf
QUOTE
The iron-rich component of the WTC dust sample was analyzed in some detail by scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (X-EDS). Using the scanning electron microscope, we found that much of the iron-rich dust was in fact composed of roughly spherical particles – microspheres. The presence of metallic microspheres implies that these metals were once molten, so that surface tension pulled the droplets into a roughly spherical shape. Then the molten droplets solidified in air, preserving the information that they were once molten in the spherical shape as well as chemical information.
Iron melts at 1538 oC, so the presence of these numerous iron-rich spheres implies a very high temperature. Too hot in fact for the fires in the WTC buildings since jet fuel (kerosene), paper and wood furniture – and other office materials – cannot reach the temperatures needed to melt iron or steel. (Remember the wood-burning stove…) Of course, elemental sulfur as found in thermate can lower the melting point of steel as discussed above.
As usual, we search for possible prosaic explanations for these metallic spherules in the WTC dust. The most obvious possible source is the melting of large quantities of steel in the buildings followed somehow by formation of tiny droplets of molten steel. As discussed above, however, steel melts at about 1538 oC (2800 oF) – and the temperatures in the buildings were no where near hot enough to melt steel, and certainly not in large quantities required for the amounts seen in the dust (and pouring out of the South Tower before collapse).
1538 degrees centigrade.
Dr. Frank Greening referred to these microspheres as "the great mystery of 9/11". Maybe a bit dramatic, but then again, maybe exactly where this is all headed.
LOOKING UNTO JESUS THE AUTHOR AND FINISHER OF OUR FAITH
WHO FOR THE JOY THAT WAS SET BEFORE HIM
ENDURED THE CROSS
DESPISING THE SHAME
AND IS SET DOWN AT THE RIGHT HAND OF THE THRONE OF GOD
QUOTE (Grumpy+May 15 2007, 01:31 PM)
Other examples of Craig t. Furlongs Lyin-for-Jesus
Evidence??? Craig don't need no stinkin' evidence, he just knows(did Jesus tell him?).
Well, DUH!!! It was only hit by hundreds of tons of steel from WTC1.
HORSE POO!!!
So???
The first true statement in his whole diatribe, will it cause him to think about the impossibility of doing this work unobserved???
Nope, no thinking will be done when Craig is in charge, notice his switch of topics here. If the evidence shows your fantasy to be impossible, ignore it(or continue to INSIST it is real, like firetruck reflections, eh, Craig???)
What is there to refute, all I see is your claims and lies, Craig. And the rantings of a paranoid nitwit!!!
Grumpy
You search the internet for information on me.
That's nice. I stand by every word I have written.
But understand this, this is not about me.
It is about justice regarding 9/11 (something you are unfamiliar with).
Many of the family members of those who died want justice very badly, and yet you write your erroneous, illogical rant about how the "9/11 conspiracy tin-foil nutters" disgrace the memory of those who died {to paraphrase your garbage}.
This is so very wrong on your part.
Do you want justice for 9/11 as much as those family members?
I think not.
If you did, you would not impede the efforts of these family members who desire and thirst for justice for their departed ones. Anyone who impedes their efforts for justice regarding this are totally wrong.
I do not write to you.
I write to those who understand what I am saying.
I want justice for 9/11 as much as those family members.
THE GRASS WITHERS THE FLOWERS FADE
BUT THE WORD OF OUR GOD STANDS FOREVER
Evidence??? Craig don't need no stinkin' evidence, he just knows(did Jesus tell him?).
Well, DUH!!! It was only hit by hundreds of tons of steel from WTC1.
HORSE POO!!!
So???
The first true statement in his whole diatribe, will it cause him to think about the impossibility of doing this work unobserved???
Nope, no thinking will be done when Craig is in charge, notice his switch of topics here. If the evidence shows your fantasy to be impossible, ignore it(or continue to INSIST it is real, like firetruck reflections, eh, Craig???)
What is there to refute, all I see is your claims and lies, Craig. And the rantings of a paranoid nitwit!!!
Grumpy
You search the internet for information on me.
That's nice. I stand by every word I have written.
But understand this, this is not about me.
It is about justice regarding 9/11 (something you are unfamiliar with).
Many of the family members of those who died want justice very badly, and yet you write your erroneous, illogical rant about how the "9/11 conspiracy tin-foil nutters" disgrace the memory of those who died {to paraphrase your garbage}.
This is so very wrong on your part.
Do you want justice for 9/11 as much as those family members?
I think not.
If you did, you would not impede the efforts of these family members who desire and thirst for justice for their departed ones. Anyone who impedes their efforts for justice regarding this are totally wrong.
I do not write to you.
I write to those who understand what I am saying.
I want justice for 9/11 as much as those family members.
THE GRASS WITHERS THE FLOWERS FADE
BUT THE WORD OF OUR GOD STANDS FOREVER
QUOTE (Grumpy+May 15 2007, 06:03 PM)
einsteen
http://img326.imageshack.us/img326/2438/wtc7vj.png
This is not a perfect illustration(the external frames collapse first, then the overloaded core snaps, then the floors start "bagelling(DBB)) but it illustrates fairly well the sequence.
Grumpy
You mean that after plane impact there was already a collapse within the perimeter frame, probably some floors. Your first arrow is in the order of seconds-minutes. The global collapse of course something in which there is no time to weak anything. If you accept the official theory then you could reproduce the collapse if you only remove some supporting structures below floor 110-n, n>4
http://img326.imageshack.us/img326/2438/wtc7vj.png
This is not a perfect illustration(the external frames collapse first, then the overloaded core snaps, then the floors start "bagelling(DBB)) but it illustrates fairly well the sequence.
Grumpy
You mean that after plane impact there was already a collapse within the perimeter frame, probably some floors. Your first arrow is in the order of seconds-minutes. The global collapse of course something in which there is no time to weak anything. If you accept the official theory then you could reproduce the collapse if you only remove some supporting structures below floor 110-n, n>4
QUOTE (Daru+May 15 2007, 06:03 PM)
A numerical simulation of the aircraft impact into the exterior columns of the World Trade Center (WTC) was done using LS-DYNA. For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams. Actual masses, material properties and dimensions of the Boeing 767 aircraft and the exterior columns of the WTC were used in this analysis. It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns. The minimum impact velocity of the aircraft to just penetrate the exterior columns would be 130 m/s. It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm
Mohammed R. Karim and Michelle S. Hoo Fatt
LOL!
Mohammed R. Karim and Michelle S. Hoo Fatt
LOL!
Something about the collapse time calculations now.
Kuttler always uses the average speed between to points to calculate the collapse time, this is good of course because you can easily prove that for constant acceleration (a matter of bringing the square root in the denominator
to the numerator), but there is a fine point of course.
If a mass m has speed v and loses energy E within a distance d then the speed afterwards is sqrt[v^2+2(gh-E/m)] but the collapse time really depends on the way E is lost, assuming it is something uniform that gives in fact an effective acceleration smaller than g and the same calculation using average velocities can be used. Now the other opposite is that the E is only lost at one point (reminds me of a delta function), in that case we have parabolic sections that you can use in your calculations and at the points where the E is lost there is a stepwise velocity change. Now in reality it will be very difficult to know how that really happens and therefore the collapse time might differ a little bit. As far as I understood Greening's paper he used the latter and ads a correction of a second afterwards. I don't know much about strain and stuff but maybe it is the difference between a parabolic function and a sinus ? Whatever, but when I made that plot to confirm DBB's 2/3 and 3/4 g in the beginning I plotted the velocity as function of the distance, in that way you can avoid to use the collapse time. I always wonder if there are more examples of E1-like models in physics.
Kuttler always uses the average speed between to points to calculate the collapse time, this is good of course because you can easily prove that for constant acceleration (a matter of bringing the square root in the denominator
to the numerator), but there is a fine point of course.
If a mass m has speed v and loses energy E within a distance d then the speed afterwards is sqrt[v^2+2(gh-E/m)] but the collapse time really depends on the way E is lost, assuming it is something uniform that gives in fact an effective acceleration smaller than g and the same calculation using average velocities can be used. Now the other opposite is that the E is only lost at one point (reminds me of a delta function), in that case we have parabolic sections that you can use in your calculations and at the points where the E is lost there is a stepwise velocity change. Now in reality it will be very difficult to know how that really happens and therefore the collapse time might differ a little bit. As far as I understood Greening's paper he used the latter and ads a correction of a second afterwards. I don't know much about strain and stuff but maybe it is the difference between a parabolic function and a sinus ? Whatever, but when I made that plot to confirm DBB's 2/3 and 3/4 g in the beginning I plotted the velocity as function of the distance, in that way you can avoid to use the collapse time. I always wonder if there are more examples of E1-like models in physics.
Its no LOL.
"The following conclusions are made from our numerical
analysis:
1. At the top speed of the aircraft (240 m/ s), about 46% of the
initial kinetic energy of the aircraft was used to damage the
columns and the aircraft. The residual impact velocity of the
aircraft after the penetration was 171 m/ s."
And I even belive that thy underestimate the wall thickness... and other thing, such as the damping system in the tower etc.
People have to keep in mind that wtc was designed to handle Boeing impact at top speed.
"The following conclusions are made from our numerical
analysis:
1. At the top speed of the aircraft (240 m/ s), about 46% of the
initial kinetic energy of the aircraft was used to damage the
columns and the aircraft. The residual impact velocity of the
aircraft after the penetration was 171 m/ s."
And I even belive that thy underestimate the wall thickness... and other thing, such as the damping system in the tower etc.
People have to keep in mind that wtc was designed to handle Boeing impact at top speed.
QUOTE
quicknthedead
I was actually amazed and appalled by the extent andthe religious zeal with which you have spewed your garbage throughout the internet. The post I quoted was particularly offensive because you claim that anyone who doesn't believe the lies you post is...
Well, I am not ignorant, don't have my head in the sand, am not afraid of the truth, nor am I in league with the bad guys and I don't see a reflection of a firetruck in the back window of a BMW, understand that 7 was brought down by debris from 1 and 7 1/2 hours of fuel fed fires and hold Osama Ben Laden and his 19 henchmen SOLELY responsible for the attacks of 911(though the incompetence of W's administration didn't do anything to stop them).
Well, I am not ignorant, don't have my head in the sand, am not afraid of the truth, nor am I in league with the bad guys and I don't see a reflection of a firetruck in the back window of a BMW, understand that 7 was brought down by debris from 1 and 7 1/2 hours of fuel fed fires and hold Osama Ben Laden and his 19 henchmen SOLELY responsible for the attacks of 911(though the incompetence of W's administration didn't do anything to stop them).
But understand this, this is not about me.
It is about justice regarding 9/11 (something you are unfamiliar with).
Of course this is all about you!!! You want to be the one who finds the smoking gun that justifies your paranoia, you want to be known throughout the kookosphere as the great Craig T. Fulong. You have spread your garbage about explosions before impact everywhere and called those who don't agree murderers.You have called the professional scientists liars and shills of the gov't and impunged the integrity of thousands of loyal Americans, saying they were complicit in the murders of our own citizens.
But it is you who are wrong, there were no explosives used anywhere in the WTC complex, no physical evidence has been found backing up your claims. IT IS JUST NOT TRUE.
Those families would be better served if the real perpitrators of that crime are brought to justice, not if some kook squad interupts their mourning at ground zero by calling firemen and police murderers, or by harrassing the lady who took the picture of the smoke from flt 93 trying to get her to admit she was "in on it", or making a living selling videos and T-shirts about their tradgedy to the like minded and the gullible.
Those families would be better served if the real perpitrators of that crime are brought to justice, not if some kook squad interupts their mourning at ground zero by calling firemen and police murderers, or by harrassing the lady who took the picture of the smoke from flt 93 trying to get her to admit she was "in on it", or making a living selling videos and T-shirts about their tradgedy to the like minded and the gullible.
Do you want justice for 9/11 as much as those family members?
I think not.
No, you don't think. Your holier than thou attitude has the same stench as that given off by the Muslim fundamentalists responsible for 911. Just as they misuse and hide behind the Koran, you hide behind the Bible and your "concern for the families". But it is really about the promotion of you and your thouroughly trashed, totally refuted "paper" to the point that you will not even admit you see firetrucks where it is impossible for you to see them all in an attempt to discredit a legitimate video proving the timeline in that paper to be WRONG. It is a lie no matter how many Bible verses you quote.
No, you desperately want to be known as the person who found the "smoking gun". And you are willing to Lie-for-Jesus if that's what it takes.
Grumpy
Could the source of these spheres be the welding done during erection???
Or they could be part of the lightweight concrete mix.
QUOTE (->
| QUOTE |
| quicknthedead You search the internet for information on me. That's nice. I stand by every word I have written. |
I was actually amazed and appalled by the extent andthe religious zeal with which you have spewed your garbage throughout the internet. The post I quoted was particularly offensive because you claim that anyone who doesn't believe the lies you post is...
QUOTE
Anyone who says otherwise is either (1) ignorant, or
(2) got his/her head so deep in the sand they are basically those of choice (1), or
(3) he/she is a coward to the truth [aka cognitive dissonance], or finally
(4) he/she is in league with the bad guys. (These are the only possible, logical choices.)
(2) got his/her head so deep in the sand they are basically those of choice (1), or
(3) he/she is a coward to the truth [aka cognitive dissonance], or finally
(4) he/she is in league with the bad guys. (These are the only possible, logical choices.)
Well, I am not ignorant, don't have my head in the sand, am not afraid of the truth, nor am I in league with the bad guys and I don't see a reflection of a firetruck in the back window of a BMW, understand that 7 was brought down by debris from 1 and 7 1/2 hours of fuel fed fires and hold Osama Ben Laden and his 19 henchmen SOLELY responsible for the attacks of 911(though the incompetence of W's administration didn't do anything to stop them).
QUOTE (->
| QUOTE |
| Anyone who says otherwise is either (1) ignorant, or (2) got his/her head so deep in the sand they are basically those of choice (1), or (3) he/she is a coward to the truth [aka cognitive dissonance], or finally (4) he/she is in league with the bad guys. (These are the only possible, logical choices.) |
Well, I am not ignorant, don't have my head in the sand, am not afraid of the truth, nor am I in league with the bad guys and I don't see a reflection of a firetruck in the back window of a BMW, understand that 7 was brought down by debris from 1 and 7 1/2 hours of fuel fed fires and hold Osama Ben Laden and his 19 henchmen SOLELY responsible for the attacks of 911(though the incompetence of W's administration didn't do anything to stop them).
But understand this, this is not about me.
It is about justice regarding 9/11 (something you are unfamiliar with).
Of course this is all about you!!! You want to be the one who finds the smoking gun that justifies your paranoia, you want to be known throughout the kookosphere as the great Craig T. Fulong. You have spread your garbage about explosions before impact everywhere and called those who don't agree murderers.You have called the professional scientists liars and shills of the gov't and impunged the integrity of thousands of loyal Americans, saying they were complicit in the murders of our own citizens.
But it is you who are wrong, there were no explosives used anywhere in the WTC complex, no physical evidence has been found backing up your claims. IT IS JUST NOT TRUE.
QUOTE
Many of the family members of those who died want justice very badly, and yet you write your erroneous, illogical rant about how the "9/11 conspiracy tin-foil nutters" disgrace the memory of those who died {to paraphrase your garbage}.
Those families would be better served if the real perpitrators of that crime are brought to justice, not if some kook squad interupts their mourning at ground zero by calling firemen and police murderers, or by harrassing the lady who took the picture of the smoke from flt 93 trying to get her to admit she was "in on it", or making a living selling videos and T-shirts about their tradgedy to the like minded and the gullible.
QUOTE (->
| QUOTE |
| Many of the family members of those who died want justice very badly, and yet you write your erroneous, illogical rant about how the "9/11 conspiracy tin-foil nutters" disgrace the memory of those who died {to paraphrase your garbage}. |
Those families would be better served if the real perpitrators of that crime are brought to justice, not if some kook squad interupts their mourning at ground zero by calling firemen and police murderers, or by harrassing the lady who took the picture of the smoke from flt 93 trying to get her to admit she was "in on it", or making a living selling videos and T-shirts about their tradgedy to the like minded and the gullible.
Do you want justice for 9/11 as much as those family members?
I think not.
No, you don't think. Your holier than thou attitude has the same stench as that given off by the Muslim fundamentalists responsible for 911. Just as they misuse and hide behind the Koran, you hide behind the Bible and your "concern for the families". But it is really about the promotion of you and your thouroughly trashed, totally refuted "paper" to the point that you will not even admit you see firetrucks where it is impossible for you to see them all in an attempt to discredit a legitimate video proving the timeline in that paper to be WRONG. It is a lie no matter how many Bible verses you quote.
QUOTE
I want justice for 9/11 as much as those family members.
No, you desperately want to be known as the person who found the "smoking gun". And you are willing to Lie-for-Jesus if that's what it takes.
Grumpy
Daru
Some have said that, but that doesn't make it so and NIST found only a one page memoranda in the entire design package that even mentions a 707, and not one calculation or analysis. And that memo was written AFTER the design was finalized(in response to an article in the NY Times about the B25 that hit the Empire State building). That paper is about a 707 in LANDING configuration, lost in fog at ~175 mph and the fuel load was not even considered.
Besides, those buildings DID survive the initial impacts, it was the fires that further weakened the already compromised structure to the point of collapse.
Grumpy
QUOTE
People have to keep in mind that wtc was designed to handle Boeing impact at top speed.
Some have said that, but that doesn't make it so and NIST found only a one page memoranda in the entire design package that even mentions a 707, and not one calculation or analysis. And that memo was written AFTER the design was finalized(in response to an article in the NY Times about the B25 that hit the Empire State building). That paper is about a 707 in LANDING configuration, lost in fog at ~175 mph and the fuel load was not even considered.
Besides, those buildings DID survive the initial impacts, it was the fires that further weakened the already compromised structure to the point of collapse.
Grumpy
QUOTE (Daru+May 16 2007, 01:16 PM)
Its no LOL.
"The following conclusions are made from our numerical
analysis:
1. At the top speed of the aircraft (240 m/ s), about 46% of the
initial kinetic energy of the aircraft was used to damage the
columns and the aircraft. The residual impact velocity of the
aircraft after the penetration was 171 m/ s."
And I even belive that thy underestimate the wall thickness... and other thing, such as the damping system in the tower etc.
People have to keep in mind that wtc was designed to handle Boeing impact at top speed.
LOL!
And they forgot that Aluminum burns on contact with air at 2800c, they factored in the hardness of Aluminum not aluminum oxide that covers it.
The study is totally useless, that is what is LOL! Aluminum burns its way though much like depleted Uranium!
Impact of Aluminum on steel.
They forgot to factor in the burning of aluminum on impact and the hardness of Aluminum Oxide into the study major and critical flaws in the study!
"The following conclusions are made from our numerical
analysis:
1. At the top speed of the aircraft (240 m/ s), about 46% of the
initial kinetic energy of the aircraft was used to damage the
columns and the aircraft. The residual impact velocity of the
aircraft after the penetration was 171 m/ s."
And I even belive that thy underestimate the wall thickness... and other thing, such as the damping system in the tower etc.
People have to keep in mind that wtc was designed to handle Boeing impact at top speed.
LOL!
And they forgot that Aluminum burns on contact with air at 2800c, they factored in the hardness of Aluminum not aluminum oxide that covers it.
The study is totally useless, that is what is LOL! Aluminum burns its way though much like depleted Uranium!
Impact of Aluminum on steel.
They forgot to factor in the burning of aluminum on impact and the hardness of Aluminum Oxide into the study major and critical flaws in the study!
QUOTE (Daru+May 15 2007, 08:39 PM)
Yes. I know. MIT say this:
Table 3. Distribution of energy lost in the local damage of the TWC Towers. The energy is in the unit of MJ.
........................North ...................South
Airplane ..........586-23% ................586-25%
Exterior ...........103-4% .................122-3%
Floors .............1221-48% ...............1925-53%
Core columns ...630-25% ................1025-28%
Total................ 2540-100% .............3658-100%
So, why does Mohammed R. Karim and Michelle S. Hoo Fatt say 46% only to damage exterior columns.
Because theirs was a SIMPLIFIED analysis.
Also they DIDN'T say that it took 46% to damage ONLY the exterior columns.
They said:
1. At the top speed of the aircraft (240 m/ s), about 46% of the
initial kinetic energy of the aircraft was used to damage the
columns and the aircraft. The residual impact velocity of the
aircraft after the penetration was 171 m/ s."
So they said its 46% to destroy the aircraft and the columns. Which, of course is much closer to the MIT numbers.
But here's the GLITCH in their logic.
The reduction in energy they calculate is based soley on the difference in the speed of the aircraft (240 m/s vs 171 m/s) AFTER penetration. BUT, that reduction in velocity during the penetration ALSO involves destruction of quite a bit of flooring.
Arthur
Table 3. Distribution of energy lost in the local damage of the TWC Towers. The energy is in the unit of MJ.
........................North ...................South
Airplane ..........586-23% ................586-25%
Exterior ...........103-4% .................122-3%
Floors .............1221-48% ...............1925-53%
Core columns ...630-25% ................1025-28%
Total................ 2540-100% .............3658-100%
So, why does Mohammed R. Karim and Michelle S. Hoo Fatt say 46% only to damage exterior columns.
Because theirs was a SIMPLIFIED analysis.
Also they DIDN'T say that it took 46% to damage ONLY the exterior columns.
They said:
1. At the top speed of the aircraft (240 m/ s), about 46% of the
initial kinetic energy of the aircraft was used to damage the
columns and the aircraft. The residual impact velocity of the
aircraft after the penetration was 171 m/ s."
So they said its 46% to destroy the aircraft and the columns. Which, of course is much closer to the MIT numbers.
But here's the GLITCH in their logic.
The reduction in energy they calculate is based soley on the difference in the speed of the aircraft (240 m/s vs 171 m/s) AFTER penetration. BUT, that reduction in velocity during the penetration ALSO involves destruction of quite a bit of flooring.
Arthur
QUOTE (quicknthedead+May 16 2007, 12:07 AM)
Dr. Frank Greening referred to these microspheres as "the great mystery of 9/11". Maybe a bit dramatic, but then again, maybe exactly where this is all headed.
Except someone with EXPERIENCE in this field (unlike the chemist Greening) claims that they are NO MYSTERY and in fact WERE TO BE EXPECTED.
See: http://forum.physorg.com/index.php?showtop...ndpost&p=190080
Arthur
Except someone with EXPERIENCE in this field (unlike the chemist Greening) claims that they are NO MYSTERY and in fact WERE TO BE EXPECTED.
See: http://forum.physorg.com/index.php?showtop...ndpost&p=190080
Arthur
QUOTE (einsteen+May 16 2007, 12:58 PM)
I always wonder if there are more examples of E1-like models in physics.
Yes there are. Or anyway, in aerospace engineering. The e-mail I saw somewhere was not particular clear, but it appeared to me to be saying that the B & V crush-down equation had already been previously used in some studies related to the International Space Station. I'm guessing that it was in relation to docking the space shuttle, so the forces applied were much less than [I]g{/I]!
On another matter, your sequence of visual aids does not seem quite right to me. Consider WTC 1.
(1) Exterior walls buckle, transferring loads to surviving core columns.
(2) Core columns buckle, column line by column line, south to north.
(3) Top block (zone A) tilts to the south.
(4) South side of zone A beings to impact the next floor down at 0.8 seconds and 4 arc-degrees.
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
Yes there are. Or anyway, in aerospace engineering. The e-mail I saw somewhere was not particular clear, but it appeared to me to be saying that the B & V crush-down equation had already been previously used in some studies related to the International Space Station. I'm guessing that it was in relation to docking the space shuttle, so the forces applied were much less than [I]g{/I]!
On another matter, your sequence of visual aids does not seem quite right to me. Consider WTC 1.
(1) Exterior walls buckle, transferring loads to surviving core columns.
(2) Core columns buckle, column line by column line, south to north.
(3) Top block (zone A) tilts to the south.
(4) South side of zone A beings to impact the next floor down at 0.8 seconds and 4 arc-degrees.
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
QUOTE (David B. Benson+May 16 2007, 02:22 PM)
On another matter, your sequence of visual aids does not seem quite right to me. Consider WTC 1.
(1) Exterior walls buckle, transferring loads to surviving core columns.
(2) Core columns buckle, column line by column line, south to north.
(3) Top block (zone A) tilts to the south.
(4) South side of zone A beings to impact the next floor down at 0.8 seconds and 4 arc-degrees.
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
Commentary on David's description of the collapse of WTC 2:
(1) Exterior walls buckle, transferring loads to surviving core columns.
==> The exterior column buckling is occuring over ~ three floors. When these exterior columns buckle the support for the floors also is lost and so the core columns lose much of their restraint against outward horizontal movement over a span of several floors.
(2) Core columns buckle, column line by column line, south to north.
==> The key SE Corner column and its neighbors were taken out by the plane, the tower is already leaning to the Southeast because of it. Fire has already caused numerous detachments of flooring to the outside columns in the North East quadrant. As the Core columns buckle, many of the truss seats are damaged and parts of the flooring begin to fail, falling onto the floors below.
(3) Top block (zone A) tilts to the south.
==> and East.
(4) South side of zone A beings to impact the next floor down at 0.8 seconds and 4 arc-degrees.
==>Because of the impact of the fires and floor failures that occur as part of the buckling there is likely no significant impacts of Zone A into relatively normal floor trusses for several floor levels.
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
Arthur
(1) Exterior walls buckle, transferring loads to surviving core columns.
(2) Core columns buckle, column line by column line, south to north.
(3) Top block (zone A) tilts to the south.
(4) South side of zone A beings to impact the next floor down at 0.8 seconds and 4 arc-degrees.
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
Commentary on David's description of the collapse of WTC 2:
(1) Exterior walls buckle, transferring loads to surviving core columns.
==> The exterior column buckling is occuring over ~ three floors. When these exterior columns buckle the support for the floors also is lost and so the core columns lose much of their restraint against outward horizontal movement over a span of several floors.
(2) Core columns buckle, column line by column line, south to north.
==> The key SE Corner column and its neighbors were taken out by the plane, the tower is already leaning to the Southeast because of it. Fire has already caused numerous detachments of flooring to the outside columns in the North East quadrant. As the Core columns buckle, many of the truss seats are damaged and parts of the flooring begin to fail, falling onto the floors below.
(3) Top block (zone A) tilts to the south.
==> and East.
(4) South side of zone A beings to impact the next floor down at 0.8 seconds and 4 arc-degrees.
==>Because of the impact of the fires and floor failures that occur as part of the buckling there is likely no significant impacts of Zone A into relatively normal floor trusses for several floor levels.
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
Arthur
QUOTE (adoucette+May 16 2007, 07:46 PM)
Commentary on David's description of the collapse of WTC 2:
...
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
I was summarizing WTC 1.
WTC 2 was indeed different.
For WTC 2 the tilting and (rotation) is much more than a mere 8 arc-degrees...
Edited to add: Initially only three walls of WTC 1 buckled. The north wall broke apart when the tilting reached 8 arc-degrees.
...
(5) At 8 arc-degrees, tilting stops and the tilted top block is bageling its way though the floors.
I was summarizing WTC 1.
WTC 2 was indeed different.
For WTC 2 the tilting and (rotation) is much more than a mere 8 arc-degrees...
Edited to add: Initially only three walls of WTC 1 buckled. The north wall broke apart when the tilting reached 8 arc-degrees.
OOPS
Dynamic response of the lower portion of the towers (conclusion):
First of all, compliances add. That is, suspending one coiled spring from a fixed stand and then attaching another spring below to the first, the compliance of the compound spring is the sum of the two compliances. So yesterday's post regarding integrating from the differential form to obtain the period of the conical cylinder section would have been clearer if written in terms of compliances, although it would formally be the same.
Using the formula for the compliance of the entire column with cross sectional area given by
A(x) = ax + b
I put in some numbers for a and b which approximate the growth of the cross section for core columns in the towers from the very top down to the lowest subbasement 437 meters below. Note that for this height, the half-period is T/2 = 0.18 seconds. In any case, the rough estimate ( +/- 20% ) for the compliance is
C ~ 10^(-8)
Now from measurements, at T/2 the top of WTC 1 dropped about 0.1+ meters. Assume this is entirely due to the elastic response of all of the core columns. We then have
0.1 = 2x10^(-8) P
and this occurs approximately in free-fall ( 0.7 g ) so solving for P and then P = Mg we get
M ~ 500 tonnes.
This is about right ( +/- 30% ) for the excess load added to each surviving core column by the buckling of three walls!
So it may well have been that no core column buckling occurred before about 0.2 seconds, due to the dynamic response of the core columns as (large) distributed mass-spring systems. However, after that time, the spring is unloading upwards while the excess weight is pressing downwards. Whatever member of the column which first significantly exceeds its DCR fails. I opine this was in the fire and impact damaged stories and than the failures occurred column line by column line from south to north.
This approximate analysis should be enough to put quietus to the claims that the elastic response of the lower portion of the towers could somehow prevent global collapse.
I am now ready for any remarks or comments.
First of all, compliances add. That is, suspending one coiled spring from a fixed stand and then attaching another spring below to the first, the compliance of the compound spring is the sum of the two compliances. So yesterday's post regarding integrating from the differential form to obtain the period of the conical cylinder section would have been clearer if written in terms of compliances, although it would formally be the same.
Using the formula for the compliance of the entire column with cross sectional area given by
A(x) = ax + b
I put in some numbers for a and b which approximate the growth of the cross section for core columns in the towers from the very top down to the lowest subbasement 437 meters below. Note that for this height, the half-period is T/2 = 0.18 seconds. In any case, the rough estimate ( +/- 20% ) for the compliance is
C ~ 10^(-8)
Now from measurements, at T/2 the top of WTC 1 dropped about 0.1+ meters. Assume this is entirely due to the elastic response of all of the core columns. We then have
0.1 = 2x10^(-8) P
and this occurs approximately in free-fall ( 0.7 g ) so solving for P and then P = Mg we get
M ~ 500 tonnes.
This is about right ( +/- 30% ) for the excess load added to each surviving core column by the buckling of three walls!
So it may well have been that no core column buckling occurred before about 0.2 seconds, due to the dynamic response of the core columns as (large) distributed mass-spring systems. However, after that time, the spring is unloading upwards while the excess weight is pressing downwards. Whatever member of the column which first significantly exceeds its DCR fails. I opine this was in the fire and impact damaged stories and than the failures occurred column line by column line from south to north.
This approximate analysis should be enough to put quietus to the claims that the elastic response of the lower portion of the towers could somehow prevent global collapse.
I am now ready for any remarks or comments.
Codicil --- All the above assumed that the load was instantly transfered from instantly broken walls onto the surviving core columns, a sudden load of infinite duration, sometimes called a step function.
More realistic is a ramp function which grows linearly up to the maximum and retains that maximum value thereafter. The ramp-up takes some time, call it u. What has gone before assumed u=0. But if u is positive, in general the response of the core column will be less than the maximum response previously estimated. It can never be more and for some values of u can even be (theoretically) zero.
So the above analysis represents the maximum case which might have occurred. I rest my case (at least for today).
More realistic is a ramp function which grows linearly up to the maximum and retains that maximum value thereafter. The ramp-up takes some time, call it u. What has gone before assumed u=0. But if u is positive, in general the response of the core column will be less than the maximum response previously estimated. It can never be more and for some values of u can even be (theoretically) zero.
So the above analysis represents the maximum case which might have occurred. I rest my case (at least for today).
[removed]
Leave it to newton to try to minimize or make fun of thousands of people dying.
Truely one of the most PATHETIC posts ever made in these threads.
Arthur
Truely one of the most PATHETIC posts ever made in these threads.
Arthur
QUOTE (adoucette+May 17 2007, 04:18 AM)
Leave it to newton to try to minimize or make fun of thousands of people dying.
Truely one of the most PATHETIC posts ever made in these threads.
Arthur
that's what i thought, too. (except the leave it to newton part. i feel nearly as bad when i have to quote FEMA or NIST lies and obfuscations.)
i put it here for posterity. i didn't create it.
Truely one of the most PATHETIC posts ever made in these threads.
Arthur
that's what i thought, too. (except the leave it to newton part. i feel nearly as bad when i have to quote FEMA or NIST lies and obfuscations.)
i put it here for posterity. i didn't create it.
QUOTE (adoucette+May 17 2007, 04:18 AM)
Leave it to newton to try to minimize or make fun of thousands of people dying.
Truely one of the most PATHETIC posts ever made in these threads.
Arthur
I'm sure Will Smith would appreciate being used by Truthers to mock the tragedy of 9/11.
http://www.youtube.com/watch?v=FmBPnDPtkRo
Maybe we should send him an e-mail with a link to this page so he can thank newton.
Truely one of the most PATHETIC posts ever made in these threads.
Arthur
I'm sure Will Smith would appreciate being used by Truthers to mock the tragedy of 9/11.
http://www.youtube.com/watch?v=FmBPnDPtkRo
Maybe we should send him an e-mail with a link to this page so he can thank newton.
QUOTE (Capracus+May 17 2007, 05:52 AM)
I'm sure Will Smith would appreciate being used by Truthers to mock the tragedy of 9/11.
http://www.youtube.com/watch?v=FmBPnDPtkRo
Maybe we should send him an e-mail with a link to this page so he can thank newton.
maybe will smith is a conspiracy theorist.
once again. i didn't create this, dawg.
edit to add, did you know they changed the ending of M.I.B.? originally, the twin towers were the site of a covert spaceport. they changed the ending after the towers were destroyed(and perhaps, i'm guessing, they then substituted the world expo site instead).
http://www.youtube.com/watch?v=FmBPnDPtkRo
Maybe we should send him an e-mail with a link to this page so he can thank newton.
maybe will smith is a conspiracy theorist.
once again. i didn't create this, dawg.
edit to add, did you know they changed the ending of M.I.B.? originally, the twin towers were the site of a covert spaceport. they changed the ending after the towers were destroyed(and perhaps, i'm guessing, they then substituted the world expo site instead).
QUOTE (adoucette+May 16 2007, 04:25 PM)
Except someone with EXPERIENCE in this field (unlike the chemist Greening) claims that they are NO MYSTERY and in fact WERE TO BE EXPECTED.
See: http://forum.physorg.com/index.php?showtop...ndpost&p=190080
Arthur
YOU have only one problem Arthur that link is pre NIST when it was believed the fires burn hot enough to melt steel and form the spheres.
NIST's conclusions make that unlikely, so the spheres have to come from some other source, or the temperatures in the fires as listed by NIST are off by several degrees.
However I know of only 5 or six ways the spheres could have formed without thermite or thermate or controlled demolition but they do point to problems in Nists Hypothesis and experimental data.
I do not believe the theory of controlled demolition is sound, but I do not believe that NIST hypothesis accurately describes the formation of the spheres.
I believe that the fire tests were not accurate, because NIST Neglected the potential of Chemical reactions occurring in the fires.
See: http://forum.physorg.com/index.php?showtop...ndpost&p=190080
Arthur
YOU have only one problem Arthur that link is pre NIST when it was believed the fires burn hot enough to melt steel and form the spheres.
NIST's conclusions make that unlikely, so the spheres have to come from some other source, or the temperatures in the fires as listed by NIST are off by several degrees.
However I know of only 5 or six ways the spheres could have formed without thermite or thermate or controlled demolition but they do point to problems in Nists Hypothesis and experimental data.
I do not believe the theory of controlled demolition is sound, but I do not believe that NIST hypothesis accurately describes the formation of the spheres.
I believe that the fire tests were not accurate, because NIST Neglected the potential of Chemical reactions occurring in the fires.
Chainsaw
Could the source of these spheres be the welding done during erection??? The collapse would have spread them far and wide from all the nooks and cranies they had been hiding in for years. I don't know of any construction site which is completely cleaned of this type of particle, do you???
Grumpy
Could the source of these spheres be the welding done during erection??? The collapse would have spread them far and wide from all the nooks and cranies they had been hiding in for years. I don't know of any construction site which is completely cleaned of this type of particle, do you???
Grumpy
QUOTE (Chainsaw+,May 17 2007, 08:33 AM)
YOU have only one problem Arthur that link is pre NIST when it was believed the fires burn hot enough to melt steel and form the spheres.
NIST's conclusions make that unlikely, so the spheres have to come from some other source, or the temperatures in the fires as listed by NIST are off by several degrees.
However I know of only 5 or six ways the spheres could have formed without thermite or thermate or controlled demolition but they do point to problems in Nists Hypothesis and experimental data.
I do not believe the theory of controlled demolition is sound, but I do not believe that NIST hypothesis accurately describes the formation of the spheres.
I believe that the fire tests were not accurate, because NIST Neglected the potential of Chemical reactions occurring in the fires.
Dr Lee would not likely have been so inclined:
Dr. Richard J. Lee has spent 30 years developing techniques for
characterizing respirable particles. Dr. Lee has used these techniques to
investigate dust and debris in buildings throughout the United States. He
has studied respirable asbestos, mineral wool, lead, fly ash, and other
particle types found in WTC Dust. He is widely regarded as a pioneer in this
area, having developed the first computer-controlled electron microscope
methods for determining the size and composition of airborne particles in an
automated fashion. As early as 1980, he was retained by EPA to design a
state-of-the-art particle characterization laboratory. His laboratory, RJ Lee
Group, Inc., is the largest commercial electron microscope laboratory in the
world. His company employs over 200, including personnel with advanced
and specialized degrees in the areas of biology, chemistry, mineralogy,
physics, geology, chemical engineering, electrical engineering, computer
science, materials science, environmental science/engineering, civil
engineering, mechanical engineering and industrial hygiene. Dr. Lee has
published more than 100 papers in peer-reviewed journals, and has
presented invited papers both nationally and internationally.
What he said:
Considering the high temperatures reached during the destruction of
the WTC, the following three types of combustion products would be
expected to be present in WTC Dust. These products are:
• Vesicular carbonaceous particles primarily from plastics
• Iron-rich spheres from iron-bearing building components or contents
• High temperature aluminosilicate from building materials
He didn't say WHY he expected them, only THAT THEY WERE EXPECTED.
I agree with you Chainsaw, NIST left out many of the things that would have added heat to the fire (and even localized intense heat) as they were being CONSERVATIVE.
Their model showed that WITHOUT accounting for these MISCELLANEOUS sources there was sufficient energy in the building materials to bring down the towers.
Arthur
NIST's conclusions make that unlikely, so the spheres have to come from some other source, or the temperatures in the fires as listed by NIST are off by several degrees.
However I know of only 5 or six ways the spheres could have formed without thermite or thermate or controlled demolition but they do point to problems in Nists Hypothesis and experimental data.
I do not believe the theory of controlled demolition is sound, but I do not believe that NIST hypothesis accurately describes the formation of the spheres.
I believe that the fire tests were not accurate, because NIST Neglected the potential of Chemical reactions occurring in the fires.
Dr Lee would not likely have been so inclined:
Dr. Richard J. Lee has spent 30 years developing techniques for
characterizing respirable particles. Dr. Lee has used these techniques to
investigate dust and debris in buildings throughout the United States. He
has studied respirable asbestos, mineral wool, lead, fly ash, and other
particle types found in WTC Dust. He is widely regarded as a pioneer in this
area, having developed the first computer-controlled electron microscope
methods for determining the size and composition of airborne particles in an
automated fashion. As early as 1980, he was retained by EPA to design a
state-of-the-art particle characterization laboratory. His laboratory, RJ Lee
Group, Inc., is the largest commercial electron microscope laboratory in the
world. His company employs over 200, including personnel with advanced
and specialized degrees in the areas of biology, chemistry, mineralogy,
physics, geology, chemical engineering, electrical engineering, computer
science, materials science, environmental science/engineering, civil
engineering, mechanical engineering and industrial hygiene. Dr. Lee has
published more than 100 papers in peer-reviewed journals, and has
presented invited papers both nationally and internationally.
What he said:
Considering the high temperatures reached during the destruction of
the WTC, the following three types of combustion products would be
expected to be present in WTC Dust. These products are:
• Vesicular carbonaceous particles primarily from plastics
• Iron-rich spheres from iron-bearing building components or contents
• High temperature aluminosilicate from building materials
He didn't say WHY he expected them, only THAT THEY WERE EXPECTED.
I agree with you Chainsaw, NIST left out many of the things that would have added heat to the fire (and even localized intense heat) as they were being CONSERVATIVE.
Their model showed that WITHOUT accounting for these MISCELLANEOUS sources there was sufficient energy in the building materials to bring down the towers.
Arthur
QUOTE (Grumpy+May 17 2007, 08:36 AM)
Could the source of these spheres be the welding done during erection???
Or they could be part of the lightweight concrete mix.
QUOTE (Palpatane+May 17 2007, 08:49 AM)
Or they could be part of the lightweight concrete mix.
Lightwight Iron spheres?
Lightwight Iron spheres?
QUOTE (adoucette+May 17 2007, 07:05 AM)
Dr Lee would not likely have been so inclined:
Dr. Richard J. Lee has spent 30 years developing techniques for
characterizing respirable particles. Dr. Lee has used these techniques to
investigate dust and debris in buildings throughout the United States. He
has studied respirable asbestos, mineral wool, lead, fly ash, and other
particle types found in WTC Dust. He is widely regarded as a pioneer in this
area, having developed the first computer-controlled electron microscope
methods for determining the size and composition of airborne particles in an
automated fashion. As early as 1980, he was retained by EPA to design a
state-of-the-art particle characterization laboratory. His laboratory, RJ Lee
Group, Inc., is the largest commercial electron microscope laboratory in the
world. His company employs over 200, including personnel with advanced
and specialized degrees in the areas of biology, chemistry, mineralogy,
physics, geology, chemical engineering, electrical engineering, computer
science, materials science, environmental science/engineering, civil
engineering, mechanical engineering and industrial hygiene. Dr. Lee has
published more than 100 papers in peer-reviewed journals, and has
presented invited papers both nationally and internationally.
What he said:
Considering the high temperatures reached during the destruction of
the WTC, the following three types of combustion products would be
expected to be present in WTC Dust. These products are:
• Vesicular carbonaceous particles primarily from plastics
• Iron-rich spheres from iron-bearing building components or contents
• High temperature aluminosilicate from building materials
He didn't say WHY he expected them, only THAT THEY WERE EXPECTED.
I agree with you Chainsaw, NIST left out many of the things that would have added heat to the fire (and even localized intense heat) as they were being CONSERVATIVE.
Their model showed that WITHOUT accounting for these MISCELLANEOUS sources there was sufficient energy in the building materials to bring down the towers.
Arthur
Why don’t you let us know when he gets around to explaining why he expected the steel spheres.
Until then he is about as useful as the (OCT) engineers claiming the buildings collapsed from the steel melting.
Dr. Richard J. Lee has spent 30 years developing techniques for
characterizing respirable particles. Dr. Lee has used these techniques to
investigate dust and debris in buildings throughout the United States. He
has studied respirable asbestos, mineral wool, lead, fly ash, and other
particle types found in WTC Dust. He is widely regarded as a pioneer in this
area, having developed the first computer-controlled electron microscope
methods for determining the size and composition of airborne particles in an
automated fashion. As early as 1980, he was retained by EPA to design a
state-of-the-art particle characterization laboratory. His laboratory, RJ Lee
Group, Inc., is the largest commercial electron microscope laboratory in the
world. His company employs over 200, including personnel with advanced
and specialized degrees in the areas of biology, chemistry, mineralogy,
physics, geology, chemical engineering, electrical engineering, computer
science, materials science, environmental science/engineering, civil
engineering, mechanical engineering and industrial hygiene. Dr. Lee has
published more than 100 papers in peer-reviewed journals, and has
presented invited papers both nationally and internationally.
What he said:
Considering the high temperatures reached during the destruction of
the WTC, the following three types of combustion products would be
expected to be present in WTC Dust. These products are:
• Vesicular carbonaceous particles primarily from plastics
• Iron-rich spheres from iron-bearing building components or contents
• High temperature aluminosilicate from building materials
He didn't say WHY he expected them, only THAT THEY WERE EXPECTED.
I agree with you Chainsaw, NIST left out many of the things that would have added heat to the fire (and even localized intense heat) as they were being CONSERVATIVE.
Their model showed that WITHOUT accounting for these MISCELLANEOUS sources there was sufficient energy in the building materials to bring down the towers.
Arthur
Why don’t you let us know when he gets around to explaining why he expected the steel spheres.
Until then he is about as useful as the (OCT) engineers claiming the buildings collapsed from the steel melting.
the "high temperatures" he cites are how high, exactly? pretty vague.
reasonlesswhining
Noone I have seen is claiming any such thing, that is a strawman arguement of the CT nutjobs.
Grumpy
QUOTE
Until then he is about as useful as the (OCT) engineers claiming the buildings collapsed from the steel melting.
Noone I have seen is claiming any such thing, that is a strawman arguement of the CT nutjobs.
Grumpy
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