Problems with non-linear analysis in Ansys 15 Mechanical APDL

[Dominikanon]

Hey, my problem occurs when trying to perform non-linear structural analysis for Shell 181 model in new Ansys 15. The thing is that the same analysis goes correctly for previous Ansys version (e.g. Ansys 12). However, Ansys 15 doesn't obtain convergence and the solution is made approximately only halfway.
I use typical solver options:
ANTYPE,0
NLGEOM,1
NSUBST,100,105,100
OUTRES,ERASE
OUTRES,ALL,ALL
solve

I am trying to use different solver such as Sparse,PCG,JCG however it still doesn't work. Have you ever met with such a problem, do you know what can be the reason? Probably some solver default options changed in Ansys 15 and I do know which of them. If you have any idea please share.

 

[petb]

This question is close to impossible to answer with the information you've provided. What is the physics behind your model? Strain-rate-dependency, self-contact, frictional contact, non-linear buckling? What material models are you using?

/petb

 

[Dominikanon]

Model is in fact a Z-profile which consists of 7 layers combining aluminum with composite prepreg. Concerning boundary conditions, the geometry is simply supported and one edge of profile is subjected to uniform pressure causing compressive stress state. I already performed linear eigen-buckling analysis which works perfectly however problems occurs with non-linear buckling.

 

[Dominikanon]

Performing Timhist Postpro analysis and trying to see one of the nodes displacement the results shows only one value of displacement (I am using option- save every substep in soln control). Nevertheless, I cannot draw any graph.