-
1
- #1
fea123
Automotive
- Oct 4, 2001
- 3
Hi,
My experience is that I can generally predict good displacements and forces with my code of choice (Abaqus) that correlate to test for several projects that I work on.
Unfortunately, whether I like it or not, stress is used as a "failure criterion" with design groups at companies that I consult with, they like their stress analysis simplified to the level of color coded traffic lights.
A particularly twisted manifestation of this is people using Mises plasticity with isotropic hardening for somewhat brittle metals (powder metals or hardened metals) to perform the calculations and then blithely looking at the Maximum Principal Stress as the failure criterion. This seems inconsistent, doesn't it since the kinematics of the hardening is following ductile plasticity laws but you then look at the maximum principal stresses? I do know that people who really care about brittlesness in tension and plasticity in compression use more sophisticated plasticity models.
I was wondering if anyone who uses Mises plasticity for modeling brittle metals and then uses the Maximum Principal Stress as a failure criterion can make some strong arguments about why it might be justified.
Thanks,
Tony
My experience is that I can generally predict good displacements and forces with my code of choice (Abaqus) that correlate to test for several projects that I work on.
Unfortunately, whether I like it or not, stress is used as a "failure criterion" with design groups at companies that I consult with, they like their stress analysis simplified to the level of color coded traffic lights.
A particularly twisted manifestation of this is people using Mises plasticity with isotropic hardening for somewhat brittle metals (powder metals or hardened metals) to perform the calculations and then blithely looking at the Maximum Principal Stress as the failure criterion. This seems inconsistent, doesn't it since the kinematics of the hardening is following ductile plasticity laws but you then look at the maximum principal stresses? I do know that people who really care about brittlesness in tension and plasticity in compression use more sophisticated plasticity models.
I was wondering if anyone who uses Mises plasticity for modeling brittle metals and then uses the Maximum Principal Stress as a failure criterion can make some strong arguments about why it might be justified.
Thanks,
Tony
