Hello,
I'm having trouble with the masses participating to modal analysis.
In order to avoid any other errors i defined a single load (33 Masses) specialy for load to mass conversion.
I set the Direction -z, coef. = 1.00 , ->global masses
The 33Masses load is uniformly distributed at the roof level.
After i run the calculation, in the Dynamic Analysis Results table i get the Total Mass = 14442 Kg.
The mass participation for the first mode (UY direction) is only 65%.
BUT, the total UZ reactions for 33Masses load is 61kN;
Q1: Why is the toatal weight from 33Masses (=61kN) converted in 14442 Kg mass? Shouldn't it be ~6100 Kg ?
Q2: The roof elements are the only ones loaded with 33Masses. I also added a ridgid diaphragm at the roof level. Why is only 65% of the total mass participating in the first 3 modes?
I couldn't attach my model but you can find it here. http://dl.transfer.ro/transfer_ro-12nov-10a5ae9b2b8744cd.zip
Thank you in advance!
Solved! Go to Solution.
Solved by Rafal.Gaweda. Go to Solution.
Q1: Why is the toatal weight from 33Masses (=61kN) converted in 14442 Kg mass? Shouldn't it be ~6100 Kg ?
It is like that - see below:
Q2: The roof elements are the only ones loaded with 33Masses. I also added a ridgid diaphragm at the roof level. Why is only 65% of the total mass participating in the first 3 modes?
Take a look at screen shot above - 98/100 % after first 2 modes without considering selfweight.