modal Mass participation ratio vs modal load participation ratio difference

[drasticxxxx]

Hello all,


Ia m conducting dynamic analysis .

I am trying to get 90 % modal mass participation ratio, however a friend of mine told me to check modal load participation ratio instead.

Actually ,I am not convinced, although the modal load reach 99% while the modal mass reach only 70&( it should be modal mass??)

So can Anyone summarize the differences between them in in etabs?

 

[Klitor]

Since noone smarter than me replied - Let me chime in:

Did you input foundation beams/slabs in your model?

If yes - Thats your problem - Those massive concrete blocks with supoorts applied directly on them cannot be engaged with your standard 10-20 modes of vibration. Try modeling without them - only line/point supports in the base of your walls/columns.