eigenvector values

[zly123]

I use layershell element to build a shear wall structure,then I do modal analysis.I want to know how to get eigenvector values.

[kesavapraba]

Hi, Please refer to the following video content for modal analysis. You can use TCL custom command "nodeVector" to obtain the Eigen vector at specific node and specific mode number, as found in the second link below.

https://www.youtube.com/watch?v=hMzioa2 ... U&index=17

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

[zly123]

Thanks！But I don't know how to write in custom command in STKO to get nodeeigenvector.Could you show it for me?

[STKO Team]

I think you misunderstood.

If you want to visualize the mode shapes in the STKO post processor, just use the MPCORecorder and the nodal result "modesOfVibration". You will be able to visualize them in the post processor.

Instead, if you need to programmatically do it in OpenSees, then you need to write a Tcl script (if you built your model in STKO you can insert a custom Tcl script using AnalysisStep->Misc_commands->customCommand).
There you can type something like this:

Code: Select all

foreach nodeTag [getNodeTags] {
	nodeEigenvector $nodeTag $eigenvector <$dof>
}

Here the opensees doc for this function: https://opensees.berkeley.edu/wiki/inde ... or_Command