Modal Participating Mass Ratios 1

[macan1]

I would like to get references regarding "Modal Participating Mass Ratios", to get better understanding.
I am using Etabs program, response spectrum with Ritz vector, references are very limited in Etabs.
Thanks for your help.

 

[Qshake]

Without going into a long explanation behind the modal participation, you can find what your looking for in the following texts:

Dynamics of Structures: Applications to Earthquake Engineering, Anil Chopra

Structural Dynamics: An introduction to computer methods, by Craig.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[Zhuge]

yap that one is a good reference, and also you can read Structural Dynamic by Clough