nonlinearity in one direction
 

Hello everybody, I have got a problem. I want to define an orthotropic material, where Gyz will be bilinear and the other material properties are linear. I tried to use tb, aniso option but I couldn't get a nonliearity in the solution.

mp,ex,2,2 mp,ey,2,80 mp,ez,2,2 mp,gxy,2,1.43 mp,gxz,2,0.7 mp,gyz,2,1.43 mp,prxy,2,0.20 mp,prxz,2,0.20 mp,pryz,2,0.20

tb,aniso,2 tbdata,1,0.05,0.8,0.05,0.05,0.8,0.05 tbdata,7,0.05,0.8,0.05,0.05,0.8,0.05 tbdata,13,0.045,0.045,0.045,0.17,0.17,0.17

I really appreciate any help. Thanks Engin