Tower Damping ratio

Dear Jason,

Recently I have some doubt about tower damping,Usually the steel have 0.005 damping ratio we setting in the model.But Some tower have lower concrete and upper steel. There are two kinds of materials. I do not sure how much the damping ratio shoud be in the model.
Could you give me some guide ?

Best Regards

Ruiliang.Wang

Dear Ruiliang,

There is already some discussion about selecting tower damping on this forum, and in the absence of actual tower-decay measurements to calibrate against, I doubt I can provide more guidance than what has already been discussed.

Best regards,