IDA envelope

This module is visible when Incremental Dynamic Analysis has been carried out, providing the plot of peak values of base shear versus maximum values of relative displacement (drift) at the node chosen by the user (IDA parameters), as obtained in each of the dynamic runs. It is possible to plot: (i) the maximum relative displacement versus the peak base shear value found in a time-window around the maximum drift (Corresponding Base Shear), (ii) the maximum relative displacement versus the maximum base shear value recorded throughout the entire time-history (Maximum Base Shear), or (iii) the maximum base shear versus the peak relative displacement value found in a time-window around the maximum shear (Corresponding Drift). The time-window is specified by the user at the IDA parameters module of the pre-processor.

In addition, it is equally possible for users to obtain in this module the envelopes of a number of additional response quantities; displacements, velocities, accelerations, reactions, member deformations and member internal forces.