Hello,
I've been trying to have simulation replicate a physical test I did on a drive shaft. The FEA stresses seem realistic, as it failed around 43,000 in-lb. But the deformation does not, as seen in the comparison of the FEA and physical torque vs. twist graph. I'm using a true stress and true strain curve obtained through lab testing. I can't figure out why these graphs differ so much. Any help would be greately appreciated.
First thoughts,
Check your material props with the same test that they were acquired with. That will give you confidence that you have selected the right material model and that it is working.
Then, loads and restraints. Are they exactly the same?
Similarly, how are you outputting the results? Are they exactly the same?
Have you checked all your units and conversions? It looks like fea is ok except that it is offset. But the curve is also cut off. Unless I'm not reading it right, is guess it is a setup or input problem.