ElasticPP gap material causing errors

[abira]

Hi,

I am using elasticPP gap material for two node link element to model a gap spring. I get the following error:
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (74, 0)
Is elasticPP material only meant to be used for zero length elements or am I making some mistake?

Thanks
Abira Rather

[mhscott]

The material is not meant for any particular element. You have a singular stiffness matrix. You can add another material of low stiffness to the twoNodeLink.

[abira]

Thanks Prof. for the answer. If I change nothing else in my model other than the material for the twoNodeLink element, I get no errors. If I change the value of gap to 0.0 for the elasticPP gap, that also solves the error. Maybe using the gap material in series with another material will help.

Thanks