This report is only available for models with rigid, semirigid and pseudo-flexible diaphragms. This report is only available if an Eigen solution has been performed.

The Periods and Modes report lists the results of the Eigen solution, including the frequency and period, modal participation factors, modal direction factors, and modal effective mass factors for each mode included in the dynamic analysis. It also lists the mode shape for each mode.

The user is provided an option in General Criteria dialog that the user can include nodal mass components in Z-direction. This is only applicable for semirigid diaphragms. If this option is selected, the report is modified: Z-direction (vertical) values have been added to Modal Participation Factors, Modal Direction Factors, and Modal Effective Mass Factors.