Convergene Issue in Nonlinear Time History Analysis

[sarif]

Hello Support Team,

I have been trying to Nonlinear Time History Analysis of a Three Story RC building. I have used InfrmFB elements for both beams and columns with 5 integration points. I have tried all the approaches to resolve convergence issues as mentioned in the manual as well as the ones mentioned in various posts in this forum. I'm attaching the model for your reference.

https://drive.google.com/drive/folders/ ... sp=sharing

[seismosoft]

Before the analysis stops, you reach interstorey drifts more than 2%, which means very significant damage. With the small and weak columns that you have, these columns fail and they cannot sustain the gravity loads, leading to the divergence problems.
Seismosoft Support

[sarif]

Thank you for the prompt response. Also, as evident in the analysis log, several columns have reached core crushing and reinforcement fracture. Could this also be due to localisation issues associated with infrmFB elements? Are the infrmFBPH elements a preferred element class to model this class of buildings?

[seismosoft]

No, probably it is because the structure cannot sustain the loading
Seismosoft Support