Staad.Pro - Seismic loads by response spectra

Question

Hi, I need help defining seismic loads by using the response spectra line graph. I add seismic periods and accelerations in the 'Load Case Details' section (attached image). I did not use the 'Definitions' section to consider seismic. My question is how to add loads to gather seismic loads in load case 12. I have used repeat load. Is this approach correct?

DSANJU · Accepted Answer

Yes, you are correct.

DSANJU · Answer

Response to Q-1. Please check if % of the sum of mass participation in the direction of application of RS loads is at least 90%. if not, increase the number of codes to be considered in the analysis. It is evident that program is not facing any problem in modal analysis. 
 Response to Q-2. It is suggested that you apply permanent plate loading in Global direction and then use them in mass modelling in three orthogonal directions.

Aswathi A · Answer

You can use mass model generator to define the seismic weights. More details are available in the link.

How to use Mass model Generator

Applies To

Product(s): 
 STAAD.Pro

Version(s): 
 CE V22 U9 and above

Environment: 
 ALL

Area: 
 Modeling Solutions

Subarea: 
 Loading 
 …

Last edited 5 months ago in RAM | STAAD | ADINA > RAM | STAAD | ADINA Wiki

DSANJU · Answer

You need to create mass modelling over here. You need to defined the loading for dead load of the model along with required % of LL in X, Y and Z direction in the RS load case. There has been another option of defining this loads in mass reference load case. If you have a mass reference load case, the program will from mass matrix on the basis of that loading that will be used in RS loads.

DSANJU · Answer

I would like to add that you are using a very old version of STAAD.Pro. Support for V8i version has been discontinued. 
 https://www.bentley.com/en/desktop-applications 
 If your Select contract is current, please plan on upgrading to the latest Connect version. 
 https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/40058/procedure-for-downloading-staad-pro-ce

Staad.Pro - Seismic loads by response spectra

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