Critical Base Excitations of Structural Systems

A critical excitation is one that maximizes chosen response quantities subject to constraints related to duration and energy imposed on the excitation. A study of the response of single‐ and multi‐degree‐of‐freedom systems subjected to critical base excitations is presented. The effect of damping and duration of excitation on the peak response is studied. The critical peak relative displacement, relative velocity, and absolute acceleration are related to one another in the same manner as the spectral displacement, velocity, and acceleration are related in earthquake response spectra. Objective functionals for maximizing response of multi‐degree‐of‐freedom systems are developed. Examples illustrating system behavior are included, and a comparison is made of peak critical response with peak responses from a strong‐motion earthquake.