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[373352238]

I am applying dynamic relaxation in my model, with gravity and axial forces imposed in the first step. Although the relevant parameters are set as required, some nodes still exhibit non-zero velocities at the final stage. Moreover, when restarting the analysis for the second step, I observed a sudden increase in node velocities at the beginning, even before applying the new load. I suspect the dynamic relaxation might not have been effectively applied, and the process is also taking a considerable amount of time. Could you advise on how to optimize the dynamic relaxation method, or suggest alternative approaches?

[Raman Babu]

Hello,

As per the dynamic relaxation, it seems like you have losen tolerance issue. So, some dynamic effect may be present. Please tighten the tolerance value and try it. To convergence it faster,  you can try damping in the contact (VDC=20) if contacts are present & can also try after adding *DAMPING_PART_STIFFNESS card.

The other appraoches could be like Single, switched analysis( implicit -explicit switching), Implicit DR,etc. The detailed description is given in the below doc.

https://ftp.lstc.com/anonymous/outgoing/jday/bolt_preload3.pdf

Regards,

Raman Babu