Discussion Groups

Robot Structural Analysis

Distinguished Contributor
Posts: 105
Registered: ‎12-12-2011

Modal analysis

340 Views, 1 Replies
10-11-2012 02:42 AM



I am performing seismic analysis. After running modal analysis to find a how many modes to use I only get mass participation up to 55 using 60 modes.


During calculations, I receive a warning regarding eigenvalues. Is this effecting load to mass conversion?


All supports are defined as elastic.


Please help me solve this. I want mass participation over 90%.


Regards Peder



Please use plain text.
Product Support
Posts: 5,105
Registered: ‎12-17-2010

Re: Modal analysis

10-11-2012 02:51 AM in reply to: pevelor

Try to increase the number of modes. You may also try to use the pseudo modes approach.


IMHO if the warning is about missing modes then for seismic analysis then you can ignore it as your goal is mass participation rather than exact values of eigenfrequencies.


If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Please use plain text.