Dear all,
I am designing a symmetrical building with core braced frame with SAP 18. The problem is, my building has pure torsion as the first mode.
Mode 1 - T=1.318s UX=0 UY=0 RZ=77.7%
Mode 2 - T=1.168s UX=0 UY=69.3% RZ=0
Mode 3 - T=1.132s UX=70.2% UY=0 RZ=0
1. Is it...