Amplitude of mode shapes - Structural Analysis and Design - Forum - Structural Analysis and Design - Bentley Communities

# Amplitude of mode shapes

## Structural Analysis and Design

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#### Amplitude of mode shapes

• Amplitude of mode shapes

Dear All,

I am a new user of STAAD Pro and interested in the Dynamic Analysis.
From the modal calculation command, we get a frequency, a (mass) participation X-Y-Z % by mode and mode shapes. I have questions as below?

1. Can the STAAD Pro show amplitude of 1st mode, 2nd mode, 3rd mode and other mode in the output?. Or
2. Can we find the amplitude of 1st mode, 2nd mode, 3rd mode and other mode by STAAD Pro?

pvsnak@live.com

•

Answer for 1 and 2 : Yes. Use the command PRINT MODE SHAPES. The values will appear in the ANL file. You can also see them in a table in the Post processing mode's Dynamics page.

Answer for 3 : Mass participation factor is the percentage of the total mass of the structure in a given direction that contributes to the base shear for that mode.

• Dear Saraswathi.I,

Thank for your answers, and I try to do with your advice. I found the way to get mode shapes by mode with the print mode shapes command and the mode shapes is normalized (the number is show in 0 to 0.999 or 1). But I need to know the amplitude (the max. displacement) in unit mm or cm of each mode shapes. Could I ask you that

1. Can we find the amplitude (the max. displacement) in unit mm or cm of each mode shapes by STAAD Pro?.

2. Can I submit my STAAD (.std) file to you? And help to advise.