Displacement control

[rejina]

How to do displacement control analysis for ElasticPPGap material? It gives some issues in mine

[fmk]

it will give no issues as long as the matrix equation can be solved .. if you have a SDOF model and only the gap material, the K matrix will have a 0 when gap is open and so solver cannot solve it.

[rejina]

Thanks fmk for the reply.
But, I want to use ElasticPPGap just to simulate only tension behaviour as I couldn't find other such material in opensees. And I have kept zero as an initial gap

[fmk]

numerics of the model cannot be overcome .. a 0 stiffness means it cannot solve the matrix equation .. to overcome the numerical issue you could throw the material in parallel with an elastic material with a very very small stiffness value (essentially 0) and the solver will solve.