convergency error: Ansys Modelling Triaxial Test (Drucker-Prager Material Model)

[nsne]

Dear all,
Hope someone can help me with the following:
I am trying to model a triaxial test in Ansys. Which means you have a cylinder of sand. At the side a pressure is applied and at the top.

I get the following error: solution not converged at time 1.E-02 (load step 1 substep1). Run terminated.

I am using the following:
- Element type: Solid187
- Material Model1: Linear Isotropic: EX=1E+008 PRXY=0.28 & Drucker-Prager: c=100 friction angle=31 flow angle=6
- soil sample is a cylinder 50x100mm (diameter x length)
- sig1=0.5E6 N/m2 (top pressure)
- sig2= 0.1E6 N/m2 (side pressure)

Constraints:
bottom part is constraint in y direction. And the sides are marked Symmetrical.

Can you maybe advice me how to solve this error? Or do you have an example of a model?

 

[CELinOttawa]

Please post this somewhere with other ANSYS users... This is not the correct forum.