# Prob. 93 AM Struct. PPE Exam Cafe



## brbowhunter (Oct 21, 2010)

Has anyone else worked this one. THe cerm shows a completely different equation for working the problem (page 44-6) and you get a different answer. 2645psi... Any ideas on which way is correct? Thanks in advance.....

Problem 93: Structural [E0304070072]

What is most nearly the maximum shearing stress for the stress element shown?

4000 psi

5000 psi

6000 psi

8000 psi

Solution:

The maximum shearing stress on a biaxial stress element is given by the equation

The answer is B.


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## mszekely (Oct 21, 2010)

I just worked this one. You should be using equation 44.20 from the CERM. It is the same equation that PPI used with the 1/2 squared pulled outside of the square root. Be careful of your signs. The 5000 psi is in compression (negative) and the 3000 is in tension (positive) so when you add them up they equal 8000. Plug and chug for 5000psi


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## brbowhunter (Oct 21, 2010)

mszekely said:


> I just worked this one. You should be using equation 44.20 from the CERM. It is the same equation that PPI used with the 1/2 squared pulled outside of the square root. Be careful of your signs. The 5000 psi is in compression (negative) and the 3000 is in tension (positive) so when you add them up they equal 8000. Plug and chug for 5000psi


Your right... I appearantly added wrong or something.. Thanks for your help!!!


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