Review: Critical Excitation Problems for Elastic–Plastic Structures Under Simple Impulse Sequences

ABSTRACT This review paper treats critical excitation methods and discusses the possibility of a paradigm shift in nonlinear structural dynamics for building structures with hysteresis using input model transformation without structural model transformation. Long‐term key issues in the earthquake‐resistant design of building structures are combats with resonance and damping. Nonlinear resonance problems are reformulated as critical excitation problems for elastic–plastic structures under a simple impulse sequence. The double impulse (DI) with two impulses of opposite directions is introduced as a simple representative model of near‐fault pulse‐type ground motions. The interval of such impulses is treated as a parameter to derive the critical input. Another critical excitation problem is considered for elastic–plastic building structures under the multi impulse (MI) representing long‐period, long‐duration ground motions. These critical excitation problems are solved by using an energy balance approach between the kinetic energy and the strain‐dissipated energy. It is pointed out that this paradigm shift enables a smart capture of nonlinear resonance in structural dynamics, which has been thought to need intrinsic repetition of numerical computation. It is also found that this paradigm shift fills a gap between two historical hypotheses (constant energy criterion, constant displacement criterion) in the earthquake‐resistant design of building structures.