Wrong results?

[james_fraser1]

Hi all

Under "Plasticity" results, should the "equivalent stress" and "equivalent strain" roughly follow the material stress/strain curve?

I am using:

MES with Nonlinear Materials

Von-Mises curve with Isotropic Hardening

ASTM A514 steel (Yield ~ 690 MPa, Ultimate ~ 760 MPa).

Large Displacement

Updated Lagrangian

(Additional output at corner nodes)

As an example, the UTS of the marerial curve is ~758 MPa with 0.18 strain. But the analysis results show a plasticity "equivalent stress" of 764 MPa with 8.7% "equivalent strain" (clearly nowhere close to the material curve data). As "equivalent strain" is a scalar value, I add the elastic strain of 0.3% and get 9% strain. Shouldn't the analysis results follow the material curve?

If I use Total Lagrangian they appear to follow the material curve. I realise UL needs "true stress/true strain", but as a comparitor, the results should still follow the material stress strain curve should they not?

Thanks

James