can not obtain modes of vibration in eigenvalue analysis

[liyanwentj]

The eigenvalue analysis is defined following the gravity analysis.
In the postprocess, the gravity analysis results can be shown and the eigen analysis result .txt file is generated, while the mode of vibration can not be shown in the postprocess.

Mode of vibration has been selected in the recorder.

The model file is attached

[marafini.f]

Hi linyanwentj,

I just did a class on this topic, you can find the video recording and material here
https://asdeasoft.net/?get-started-webinars#w17

The eigen command does not call the command record automatically in OpenSees, so you need to add it manually.
Create a customCommand in the analysis steps and simple add the word record in it.
You will be able to visualize your results like this.

Enjoy your modelling
Francesca

[liyanwentj]

I am sorry that the model did not work after I defined the recorder in the analysis step.
Yes, I have checked your example model. My model has the same analysis steps as the example one. But the result file still has no vibration mode output.

[LuisB]

Hello liyanwentj,

As marafini.f says, the eigen command does not call the recorder, look at the attached image and check the custom command that must be added to save the modes of vibration.

record_customCommand.PNG (27.75 KiB) Viewed 2807 times

[liyanwentj]

Thanks, Luis!

It works!

Regards,
liyanwentj

[LuisB]

You're welcome!