Hi! Alan again from Argentina... I'm learning little by little here. I'm having a little issue with a nonlinear analisys static simulation.

I'm making this with a simple test specimen from ASTM D638 Method for Tensile Properties of Plastics just to be sure that I load right the stress strain curve of the material.

When I simulate it with a 2D simplification the results are excellent!

These results are practically the same that doing the math...

But when I try simulate without the 2D simulation (same material, same loads) I get this error: PCGLSS0139:Matrix is Singular or Indefinite*****************)  in the solver with any of these restraints (that would be something like the analogue with the 2D simplification restraint)

You might be asking why this guy doesn't use the 2D simplification and that's it? Well, that's because after I simulate this without 2D simplification I need to simulate a part that it isn't posible to simulate with a 2D simplification since it isn't as simple as a extruded sketch or any of the 2D simplification options.

Here is the material properties I create.

Thanks!