Eigen Analysis Result 3D Model

[laxmandahal]

Hello,

For a 3D model, how do I distinguish between eigenvalues in x and y-axis such that I can calculate the modal periods in the respective axis? I'm aware of "nodeEigenvector" to get the desired number of mode shapes at specific DOF but I can't seem to figure out how to eigenvalues in x and y dir.

I also plotted the pushover curve in x and y-dir. The slopes are somewhat similar but the periods are different in respective axis.

Any help?

[anuragiitg]

You could use post-processing commands in OpenSeesPy (Python) to visualize mode shapes of your Tcl models. See the links here,

1) A little tutorial on how to combine OpenSeesPy post-processing commands with Tcl model.
https://anuragupadhyay.weebly.com/opens ... s-tcl.html
https://openseespydoc.readthedocs.io/en ... esTcl.html

2) the command to plot mode-shapes you should use.
https://openseespydoc.readthedocs.io/en ... shape.html

[selimgunay]

You can record the eigenvectors in each mode by using the "eigen i" response type in the node recorder. By checking the eigenvectors, you can figure out the x and y modes. Depending on the geometry of your structure and the orientation of columns, it is normal not to have same periods in both directions

https://opensees.berkeley.edu/wiki/inde ... e_Recorder