Problem with mass activation due to earthquake

[TSOFA]

Hi,

I have this simple structure to analyse but when I check the modal analysis results, the mass is not activated due to seismic X, why??

[sernogostaf]

just suggestion

increase number of mode

[TSOFA]

 I tried that and it worked!! but it looks strange to me that seismic X starts to move the structure at mode 13. Don't you find it strange also?

[TSOFA]

the other thing is that Robot when I run the structure is loading mass loads to the nodes of beams at all the loading cases.  I can't understand why. It should do it only for seismic loading

[StefanoPasquini6790]

Hi,

Have you assigned the mass conversion to "dynamic mass"?

Share your model so that we can be more accurate in helping you

[teixeiranh · Accepted solution]

Check this video.