Convegence Problem

[samcivil]

Hello.
I have Convergence Problem. Please help. What should I do?

[vesna]

There is no generic solution for convergence problems. However, the first thing you should do is TO CHECK YOUR MODEL. If your eigen analysis is failing it is rather problem with the modes than with the analysis. If you confirm accuracy of your model, do your analysis in a loop as in this example: http://opensees.berkeley.edu/wiki/index ... me_Example

[samcivil]

Dear vesna,
Hello.Thaks a lot for your reply.
I dont have problem in eighen values. In fact I have to impose a set of displacements to the structure to obtain drift of points located in corners of plan. And I face with this problem.In fact, it takes 24 hours for me to obtain this for 20-storey structure. What should I do?

[vesna]

By choosing right analysis objects for your problem you can speed up the analysis greatly.

For big models it is always suggested to use one of the sparse solvers.

[samcivil]

Hello.
Thank you very much, dear vesna.