Conclusion

As soon as the element reaches the targeted failure plastic strain for a given triaxiality level, the element is eroded:

• With ICOUP=0: Damage evolution has no effect on stress softening.
• With ICOUP=1: Classic stress softening using critical damage DCRIT. The more the value of DCRIT is increased, the later the softening is applied on the stress.
• With ICOUP=2 and S-Flag=3: Only for shells, the instability curve represents the criterion that must be reached to trigger the stress softening, which implies that the beginning of the strain localization and then the necking observed especially at high stress triaxiality.
• The exponent parameter EXP is used to control the shape of the stress softening, so that it is nonlinear when EXP is different from 1.