Seismosoft | Earthquake Engineering Solutions

Thank you sir. The problem with the model in the truss element is that when I divide the bracing into four elements using truss element to model initial imperfection for buckling, the model doesn't work. I think in SeismoStruct I can not divide the truss element.
So now I am trying to model the bracing with infrmFB element connected to the joint with link . I will let you know if it works for me.
Thanks
Amy

Hi

I have a similar problem. I am trying to release the moments on my bracings in a 4 storey buildings. But I am not able to run the analysis in the Pushover analysis with M2a, M3a.. etc releases. I have tried different convergence criteria referring to seismostruct video on convergence error but without any luck . The model works in an Eigen value analysis

The type of elements that I have used for my bracings are - elastic, infrmDB (both with releases) and truss elements. But none of them seems to work. What are some suggestions that you can give?

Thanks

Using frame inelastic elements with releases in the moments at its two edges generally leads to numerical instabilities. Consider either using an elastic elfrm element with releases or a truss element for the braces.
Seismosoft Support

Yes, I have tried both the options as I mentioned above and still the convergence error occurs.

Follow the guidelines that are provided in the relevant section on the manual. Running an eigenvalue analysis will also give you good insight.
Seismosoft Support

I have actually started from the Eigen value analysis and it is only when I release the moments that the convergence problem occurs. The model works perfectly without the releases. I have also read the manual and the chapter on 'Tips to solve convergence problems'. I have done all the different steps one by one like increasing convergence norms etc. but I am still not able run the model. It starts to fail after 4-5mm in a Pushover Analysis.

Can it be that the structure has actually failed? Check in the post-processor in the Convergence tab the element or location where the divergence problems occur and then check the inelastic response of these elements.
Note also that in the case of a brace that is divided in several elements, only the start of the first and the end of the last elements need to have releases
Seismosoft Support