I have a model of a large structure consisting of ~800 surface bodies and a few springs. The surfaces all mate up nicely and I have created split lines where bodies meet up. Contact is set to bonded global. It meshes with shells perfectly, matching nodes across all the joints, and has about 130k nodes in total.
When I run a linear static analysis it meshes in 49sec and solves in 45sec. All the contacts/loads/restraints are applied correctly and the stresses/defections are what I would expect both.
I would like to run a nonlinear static analysis on the structure to determine when it starts to buckle. To do this I ramp up a small load from t=0-0.1s to set the initial condition that will allow the onset of buckling. Then I apply an increasing load from t=0.1-1s. When the analysis runs it typically jumps to very small time steps (0.01s and less) initially, and takes 5-6 hours to solve each, reaching roughly t=0.03s over a period of 15+ hours. Looking at the linear static solution for the t=0.1s loads, the deflections are small and the stresses only ~10% of yield so its certainly not in a highly nonlinear area.
I have gotten previous (and slightly simpler geometry) versions of this model to solve, taking 8-12hrs to reach t=1 in ~17 time steps. This still seems like a very long time considering each static mesh+solve cycle is <2min on its own.
What could be causing this behavior?
I am running Solidworks Simulation Premium 2013 x64 SP4.0 w/32GB ram.