Hi, I was designing a multi-storey structure in RSA, and I was using the equivelant lateral force method for ASCE 7-10.
Now I know that RSA takes the selfweight by default in the seismic calculations and any other added loads in the "Load to mass Conversion" tab.
in my case, I need RSA to ignore the selfweight and use only specified loads in the "Load to mass Conversion" tab.
How can I do that?
Thanks
Solved! Go to Solution.
Solved by StefanoPasquini6790. Go to Solution.
Thanks, So when you say that I have to ignore density, does this mean that I have to create a material with Zero density or there is another way to ignore density. I know you can check the "ignore density" in the modal analysis but there is no such option in the equivelant lateral force window option.
Thanks
@mgaafar wrote:.... I know you can check the "ignore density" in the modal analysis but there is no such option in the equivelant lateral force window option.
Thanks
That's the reason I suggested you to set a zeo value on density (weight) of your material. ( You don't have to define new material just edit the excisting one from Tools->job preferences->material->modification.. .) I don't know if there's an other way for equivalent lateral force method
If "ignore density" tab was available you could you some other tricks as Stefano proposed.
Good mornign ,
I am trying to run a modal analysis in Costa Rica Central america
I have an acceleration spectrum loaded but when run analysys forces and displacement become all zero
The Question is :
To run the analsys do I have to create an additional node at gravitational structure center , assign mass to the the node ?
Is there any mass source node in Robot ?
Thank you very much for your kind answer
If your spectrum is correct (max acceleration = 0,5m/s2), and if mass is correct (almost 1,45 mass of self weight (1.0 sw mass from modal caase defintion + 0,45 of case 18 load to mass coversion) + 0,45 load to mass of case 2) so the results are also correct but to see them you have to change scale coeff and units
If I can recall, the SW can be ignored using ignore density option in the Modal Analysis. Then Use Convert Loads to masses. Don't use load to masses if you did not uncheck this option or your seismic mass will double