Response spectrum declaration

[sellsam]

In both ETABS and SAP2000, when I declare response spectrum case data, how to declare scale factors, do I put scale factors in both x and y direction, or must I declare two seismic functions in x direction with it is scale factor, and the same in y direction.

thanks.

 

[dawn836]

you should declare two functions, every direction must has its one function with its own scale factor
you may have force apllied in two directions in same function if you have to consider orthognal effects

 

[sellsam]

hello and thanks dawn836,

it is more correct if we proceed with the second proposition , so we can have orthogonal effects, do not we.

thank you

 

[Murali27]

Sellsam

Yes, if your structure calls for orthogonal effects. Otherwise, you may need to define in two principal direction of structure to understand the distribution of modal shear.

Murali

 

[sellsam]

thanks murali.