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Convergence Issues

Posted: Wed Jul 17, 2024 4:35 pm
by alirezakh61
Dears,
I have tried to model the one-bay one-story example (distributed plasticity) provided in E-learning. However, I do not know why, during analysis, I have the convergence problem as shown (attached screenshot and the file I have created).
Regards,
Example.7z
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Re: Convergence Issues

Posted: Wed Jul 17, 2024 7:20 pm
by alirezakh61
Moreover, even when I try to run the uploaded file on the E-learning webpage (exactly the file downloaded without any modifications), this analysis problem occurs.

Re: Convergence Issues

Posted: Fri Jul 19, 2024 6:08 am
by kesavapraba
Hi, This issue is relevant in recent versions STKO+OpenSees. It is due to lower order (1 in your case) of the reference load that you set for the lateral analysis, see attached figure. I changed the order from 1 to 6, which should be comparable to the lateral capacity of the model. The model runs without issue for that value. Please note that the reference load, having either too high or lower orders, can cause ill-conditioning in the stiffness matrix and convergence will be an issue after some number of steps in the analysis.

Re: Convergence Issues

Posted: Fri Jul 19, 2024 8:23 am
by alirezakh61
Thanks for your helpful answer.

Re: Convergence Issues

Posted: Tue Jul 23, 2024 4:10 pm
by kesavapraba
You are welcome