Response Spectrum Analysis

Response Spectrum Analysis is used to determine peak displacements and member forces due to support accelerations. The "Complete Quadratic Combination" method (CQC) of combining modal responses is used to determine the peak response. This is equivalent to the "Square Root of the Sum of Squares" (SRSS) method if all modal damping ratios are zero.

Static analysis results are updated with the results of the response spectrum analysis and the sum of the reactions for each dynamic load case will be displayed. You may enter factors for scaling the results to ensure compliance with minimum base shears specified in earthquake loading codes.

A library of digitized response spectrum curves is available for the Australian and New Zealand earthquake loading codes.