1. The problem statement, all variables and given/known data
Known :
- Material : Tungsten
- Property : G7 - Drill, you can see the picture in here :
http://www.accuromm.com/drills.html
- Other information you can find here :
1. http://www.efunda.com/materials/common_mat...oustic#Acoustic
2. http://www.efunda.com/materials/common_mat...ical#Mechanical
3. http://en.wikipedia.org/wiki/Tungsten

For information : I am newbie about dynamic analysis and before this, I am analysis about static only. Can anyone help me solve this problem?? I am appreciated your helpfull and Iam so sorry to makes you busy.If anyone can tell me about the step by step, it's okay to me. o:)
The question are :
1. I want to looking for Vibration and critical point
2. do you know where I can find Structural Damping Coefficient for Tungsten??
3. How to created fungtion of Power Spectral Density
4. How to created fungtion of Frequency Responce

2. Relevant equations
http://en.wikipedia.org/wiki/Vibration

3. The attempt at a solution
I have been try this steps, but I am confucing about the next steps. :confused:
1. For Yield Stress =550 MPa, Ultimate Strength = 550-620 MPa (as known in wikipedia)
2. Allowable/Permissible Stress= 0.4 (Yield Stress) = 220 MPa
3. Safety Factor = (ultimate Stress)/(Allowable Stress) = 3

Didn't understand.

If you want to machine tungsten, you must grind it, not cut it. Beware of dust, which is increasingly considered as toxic.

Do you have any hope to compute the vibration stress during machining? Forget it, you can't. Experiment it.

By the way, damping is generally due to fasteners, sound radiation... But not to intrinsic material properties, with very few exceptions like elastomers, MnCu, sometimes austenitic stainless steel, magnesium, sometimes beryllium. In tungsten, it depends heavily on impurities. Many books assert that W dampens based on stupid crystallographic theories, but I've heard welding electrodes sound, sorry.