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MODE SHAPES TO CALCULATE PARTICIPATION FACTORS

Posted: 15 Dec 2020, 13:39
by goksoy.cem
Hello;

For pushover analysis, I need mode shapes to calculate participation function. I searched about this but I can not reach any reliable and clear information. SeismoStruct has to calculate participation factors according to mode shapes. But what are these mode shapes? I read that displacement values which are mm unit are mode shapes but it is not because participation factors are diffrent values for some modes and directions. Please help me to find mode shapes.

Thank you

Re: MODE SHAPES TO CALCULATE PARTICIPATION FACTORS

Posted: 15 Dec 2020, 14:01
by z.gronti
Dear goksoy.cem,

You may execute an eigenvalue analysis to get the modal participation factors and the normalised mode shapes.

Re: MODE SHAPES TO CALCULATE PARTICIPATION FACTORS

Posted: 15 Dec 2020, 14:04
by goksoy.cem
Dear Zoi;

How can I normalized mode shapes for every nodes?

Re: MODE SHAPES TO CALCULATE PARTICIPATION FACTORS

Posted: 15 Dec 2020, 14:20
by goksoy.cem
In other words what is SeismoStruct's assumption while normalizing mode shapes.

Re: MODE SHAPES TO CALCULATE PARTICIPATION FACTORS

Posted: 15 Dec 2020, 18:50
by seismosoft
The eigenvalue are mass normalised. However, since the relative value of the deformations are of importance you may multply all these values with a constant factor; for instance if you want the max. deformation to be unity.
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