what are the answers for 5,10, explination part of 12, and 14?

3/2/2006 8:37:13 AM

also if anyone has a correct answer for 13 it would be greatly appreciated!

3/2/2006 8:41:02 AM

13 is a graph with ThetaA on y, and ThetaM on x side. 30k is y intercept and 60k is x int

fourmula you use is

ThetaM ThetaA
______ + _________ <=1
UTS Endurance

so you get
(20K/60K)+(ThetaA/30K)=1

ThetaA=20K

[Edited on March 2, 2006 at 8:49 AM. Reason : ,]

3/2/2006 8:48:41 AM

http://courses.ncsu.edu/mse200/common/hwsolutions/SampleTest2-S06.pdf

link to the practice test if you feel like helpin me out

3/2/2006 9:13:39 AM

5. fatigue life (only one that hold the amplitude constant and varies the number of cycles)
12. Not sure if this completely explains it but its a start.... FCC metals are ductile at low temperatures and do not necessarily have a DBTT but BCC experience DBTT. The DBTT is also affected by microstructure and composition.
14. I believe it is because there will be some instantaneous deformation and as time goes on there is a force acting to deform the sample but there is also a recovery force acting. So there are 2 forces: strain hardening and recovery acting against each other at some point in the process.

...hope this helps

3/2/2006 5:21:50 PM