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?
Yes, you are correct.
Answer Verified By: lachin nuriyev
Excuse me...
THE FINAL MASS MATRIX FOR DYNAMIC ANALYSIS.
EIGEN METHOD : SUBSPACE
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NUMBER OF MODES REQUESTED = 300
NUMBER OF EXISTING MASSES IN THE MODEL = 38229
NUMBER OF MODES THAT WILL BE USED = 300
Does it mean the analysis is not correct?
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.
Thank you! but this structure is a storage tank (circular) and that means Hydrostatic pressure acting on local axis in the tank wall (vertical plates). My only choice is to apply loads on local axis