Non linear Analysis non-convergence

[alpha2012]

I am trying to model a load cycle with high strain load. It is converging for load up, but it exits with error msg "elements highly distorted" in the start of the unloading. I am removing the load using "ddele."

Any idea what could be the case or what should be done.

 

[MechanicalEngUCL]

Usually when elements are highly distorted it is due to the mesh not being adequate. Try to refine the mesh globally or just locally where you expect the highest deformations to occur.

 

[inline6]

when unloading make sure there is still a very very small amount of load applied to help with convergence. are you using the same strategy for unload i.e. number of increments, matrix update strategy, number of iterations etc etc?

 

[alpha2012]

I was using same step size definition as used for load up, I will remove load even slower. As for the mesh it is very fine at the required area.

Thanks for the tips.

 

[marche]

are you using non-linear materials?