A comprehensive review of seismic critical excitation methods for robust design

A comprehensive review of strategic methods for seismic critical excitation (worst-case input) is provided to enhance the robustness of structures in the earthquake-prone region. It is inevitable that the structures in this region are subjected to disturbances including inherent uncertainties due mainly to their low rate of occurrence and worst-case analysis is expected to play an important role in avoiding difficulties induced by such uncertainties. During the last four decades, various critical excitation methods have been proposed extensively and applied to specific structural design problems, mainly for important structures of which the failure or collapse must be absolutely avoided. The degree of criticality of the extreme responses over the corresponding structural responses to recorded ground motions, deterministic or stochastic treatment, elastic or elastic-plastic responses, earthquake input energy and energy input rate indices, system-dependent critical excitations are major concerns of discussion.