Interpreting results in Mechanica (plastic component)

[akim05]

Howdy,
I have a general question that probably does not pertain only to Pro/Mechanica. My question is with a plastic that has a young's and flexural modulus that are roughly equal, do you compare the results of your analysis with the yield values for flexural or tensile? Is pure bending achieved if the component looks like an L bracket where a horizontal load is applied to the top and bottom is bolted down?

Thanks for the help.

 

[RocketRonnie]

I'm not sure that I fully understand your question, but Mechanica materials behave linearly, i.e. the stress/strain curve is linear and takes no account of yield. Large displacement analysis can be run if the displacement is larger than the thickness of the part.

 

[akim05]

Sorry,
I'll try to explain the situation better. I've basically got a component that looks like an L bracket. Its nylon, I've ran it with a simple static analysis where the bottom of the L is connected by bolts and the top of the L has a horizontal load applied to it. Since the youngs and flexural modulus are approximately the same for the material I used the young's modulus to define the material properties. Now that I have my stress results I'm wondering if I should compare my results with the yield values for tensile or for flexural. I'm guessing that my model is behaving in pure bending (or close enough to it) so I should use the flexural yield values. Is that a valid assumption?

 

[RocketRonnie]

This is probably not a Mechanica specific question and should be posted on the FEA forum:

http://www.eng-tips.com/threadminder.cfm?pid=727

In my opinion, you should check Von Mises stress results against tensile yield values. If you are not satisfied with this, check Max and Min Principal stresses.