Convergence of Cyclic Transient Analysis in Ansys

[JK7070]

Hi,

I am trying to carry out a cyclic (tension and compression) analysis on a steel strut in Ansys WB. I am trying to obtain the force-displacement response of the strut under displacement controlled loading.

What is of primary interest is the buckling behaviour of the strut and so to model this several techniques have been applied:

1. Apply an equivalent lateral load to simulate a geometric discrepancy in the strut and

2. Simulate the geometric discrepancy of the strut by creating a new model based on the first mode shape.

The trouble is I cant get my model to converge fully when I apply either of the above two scenarios. My model will converge however if I don't simulate geometric discrepancies, i.e. assume the strut to be perfect, but this assumes no buckling which is unrealistic.

Anyone have any thoughts about convergence. I think it might have something to do with my time steps????

Regards,
JK7070

 

[JK7070]

Further to the above issue, the reason given for non-convergence is "Plasticity integration algorithm did not converge for element 5081, material 1, Chaboche model".

What exactly does this mean??

I appreciate convergence issues are answered a lot, but any info would be hugely appreciated.