eigen/ritz vectors-sap2000 1

[HalimWardag]

Who can tell me what is the difference between eigen and ritz vectors when doing dynamic analysis in SAp2000?

your help is highly appreciated

 

[IJR]

If you analyse a large model and you switch on an eigenvalue analysis, you will get a lot of modes. Most of these modes will be almost similar to one another and therefore most will not be useful.

Ritz analysis can easily remove the unnecessary modes. By the time Ritz analysis is complete, you will have a few useful modes and results will be computed from those modes.

But you need to know why you need modes anyway. Please read the manual and a little bit of dynamic analysis first before using the Ritz method.