I'll performed a non linear analysis with beam model. I would obtain in advanced post a non linear stress distribution of stress (using equivalent stress plot).
How can I obtain it?
With the advent of the solver NXN 9.0 (Femap 11.1.0) nonlinear materials for the beam elements are not supported
I don't beleive this is true, because I recently had a convergence issue involving nonlinear material on a beam element in v11.3.0. And nonlinear output for the beam element is still available.
To answer OP's question, I don't think FEMAP supports an advanced display of nonlinear beam stresses on a 3D view of the beam element. Strand7 does this well: http://www.strand7.com/webnotes/search/?q=nonlinea
Ah, I had no problem with it, I was just chiming in to try to help. I defined a plastic cutoff of 355 MPa in the Nonlinear tab of my material, which was applied to both plates and beams.
I ended up taking more nonlinear steps and that cured the problem. The strain increment was too large.
It was the middle one. I got nonlinear beam output, but the nonlinear beam plastic strain was always zero. I assumed it was because it did not yield.
However, 3930..Nonlinear Beam EndB Pt4 Eqv Stress was just at the yield point (355 MPa), indicating yielding.
My mistake. It was at 35.5 MPa. Although I did get a divergence error on a nonlinear beam at one point, I corrected the model in the meantime to have higher yield strength and finer timesteps and that solved the problem. So I'm not sure what the whole story was honestly, but it's solved.