Interpreting a negative value of equivalent plastic strain
Interpreting a negative value of equivalent plastic strain
(OP)
All,
What could result in a negative value of equivalent plastic strain??
Errors in extrapolating values from the Gauss points to the nodes or simply an elastic response within the VM yield surface? Is there a way to check this? I'm using inventor Nastran, so I can't access data at Gaussian points.
Thank you
What could result in a negative value of equivalent plastic strain??
Errors in extrapolating values from the Gauss points to the nodes or simply an elastic response within the VM yield surface? Is there a way to check this? I'm using inventor Nastran, so I can't access data at Gaussian points.
Thank you
RE: Interpreting a negative value of equivalent plastic strain
Just in case, make sure that other output variables are correct.
RE: Interpreting a negative value of equivalent plastic strain
RE: Interpreting a negative value of equivalent plastic strain
RE: Interpreting a negative value of equivalent plastic strain
RE: Interpreting a negative value of equivalent plastic strain
another day in paradise, or is paradise one day closer ?
RE: Interpreting a negative value of equivalent plastic strain
RE: Interpreting a negative value of equivalent plastic strain
why does -ve plastic strain make sense as a centroidal value ?
does -ve plastic strain mean compression ?
another day in paradise, or is paradise one day closer ?
RE: Interpreting a negative value of equivalent plastic strain
A centroidal value should be close to a corner nodal value, if a mesh is correctly refined and mesh convergence is verified. However, the codes usually call for nodal values at corners?
It's the first time I'm seeing a negative value of equivalent plastic strain, albeit it is of the order 10-6. The two explanations for this are: Extrapolation from gauss points inward toward the centroid OR Mathematically, εp is positive, like a von Mises value. I suppose that a negative value indicates an elastic response where the stress state lies on/within the VM yield surface.
Does it mean compression? Probably not, as εp is a single positive scalar value.
RE: Interpreting a negative value of equivalent plastic strain
Additionally, Inventor requires the entire stress strain curve (elastic + plastic) . When it comes to evaluating plasticity, this can create problems with smoothening of the curve in the vicinity of the proportional limit.