I have recently used SeismoStruct to perform Response Spectrum Analysis (RSA). It seems to me that there is a problem with the RSA. I was modelling a single circular column, symmetric in all directions. The problem is that the software does not apply the response spectrum in the Y direction. I thought first that the problem is with the Eigenvalue analysis, but the mode shapes and the participation factors seemed fine. I have also checked that both horizontal directions are considered from the analysis options. However, the deformation values for the Y direction is zero!!
I am not sure what is the problem. Please help me with that.