Damping of infill element

[zhwang]

Dear Seismostruct support,

I am trying to run a dynamic time-history analysis on a four storey three bay RC frame with infill panels, and I would like to add damping in the infill element.

I understand there are three different damping available in SeismoStruct. When I select mass-proportional damping for the infill element, the analysis has difficult in Convergence, and no matter how I change the convergence criteria in Project Settings, it does not work.

I also notice that there is also damping available in Project Settings, what is the difference of the damping in Project Settings and the damping in infill element? Does the damping in Project Settings mean the damping of whole structure? Does the damping in infill element only consider the damping of infill panels?

In my infill panel, T is 0.08s, and damping ratio is 8%. Could you please suggest me which type of damping is better for my structure? Thank you very much.

Best regards,
Summer

[z.gronti]

Dear zhwang,

The damping defined in the Project Settings is the global damping (i.e. for the whole structure). The damping defined at element level (within the element class) takes precedence over global damping, as described in the Help System of SeismoStruct. You may find more information about this matter in SeismoStruct User Manual and Help System, as well as in a number of posts available in the Forum.

[zhwang]

Dear Zoi,

Thank you very much for your kind reply. Is there a bug in v7.0.6 for mass damping? Since I have difficulty in Convergence for analysis with mass damping. If I delete mass damping or change mass damping to stiff damping, there is no convergence problem with my dynamic analysis. Could you please give me some suggestions? Thanks very much.

Summer

[z.gronti]

Dear zhwang,

Please take a look at the answer of Dr. Tim Huff in the following topic:
http://www.seismosoft.com/forum/viewtop ... ies#p10845