Is a negative slope permitted in a plastic MISO curve (TB,MISO)? It seems to be allowed in ANSYS 11.0.
This was unintended. A negative slope is error trapped in 12.0 (defect 72633).
The documentation below clearly states that it isn't supported.
> Nonliner Stress -Strain Materials
> 126.96.36.199. Multilinear Isotropic Hardening
...No segment can have a slope less than zero.