How to output generalized mass and generalized stiffness matrix from modal analysis?

[gooddaytogo]

Hello, everyone,

I am now doing the modal analysis for a tall building using OpenSEES, from the eigenvalue analysis I can get the natural frequencies, but I don't know how to get the generalized mass and generalized stiffness for each mode. So does anyone know how to get them from OpenSEES? Thanks.

[gooddaytogo]

Basically, I want to know how the mode shapes were normalized in OpenSEES. If anyone knows it, please tell me. Many thanks.

[selimgunay]

You can try it for a simple spring mass system with few degrees of freedom where you can generate the mass matrix yourself and figure out how the modes are normalized

[eftekhar]

hello
you can use "print A" command to get mass matrix and eigenvectors
https://opensees.berkeley.edu/wiki/index.php/PrintA