Nonlinear stochastic dynamic analysis for performance‐based earthquake engineering

Abstract

Abstract A new approach for computing seismic fragility curves for nonlinear structures for use in performance‐based earthquake engineering analysis is proposed. The approach makes use of a recently developed method for nonlinear stochastic dynamic analysis by tail‐equivalent linearization. The ground motion is modeled as a discretized stochastic process with a set of parameters that characterizes its evolutionary intensity and frequency content. For each selected response (seismic demand) threshold, a linear system is defined that has the same tail probability as the nonlinear response in first‐order approximation. Simple linear random vibration analysis with the tail‐equivalent linear system then yields the fragility curve. The approach has the advantage of avoiding the selection and scaling of recorded accelerograms and repeated time‐history analyses, which is the current practice for developing fragility curves. Copyright © 2009 John Wiley & Sons, Ltd.