Convergence Issues

[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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[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.

[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.

[alirezakh61]

Thanks for your helpful answer.

[kesavapraba]

You are welcome