PushOver in Braced Frames

[alirezaii]

hello vesna
I have a problem with pushover analysis in braced frames. In this case the analysis is very sensitive to initial camber in midspan of braces (which are used to model global buckling). As such the brace behavior is unreliable and the analysis lead to fail.
Pleas help me for modeling the buckling in these structures for pushover analysis.

Best Regards

[vesna]

How can I help you?

[alirezaii]

Hi vesna
I am very grateful if you give me a proposal to solve this problem in pushover analysis. How can I correctly model the brace buckling?
Thanks a lot.

[vesna]

PEER 2008/08 report offers one way of modeling brace buckling in OpenSees. Check it out.

[alirezaii]

Hi vesna
I read this report completely and modeled the braces based on that, but this way is sensitive to the pushover analysis.
opensees give me a negative eigenvalue in low level of interstory drifts.

[vesna]

I also modeled the brace frame following the recommendations from that report and was able to do pushover analysis.