Reliability sensitivity estimation of nonlinear structural systems under stochastic excitation: A simulation-based approach

This work explores the feasibility of using advanced simulation-based methods for reliability sensitivity analysis of nonlinear structural systems subject to stochastic excitation. Reliability is defined in terms of a first excursion probability which measures the chances that uncertain structural responses exceed in magnitude prescribed threshold levels within a specified time interval. The proposed reliability sensitivity analysis consists of applying a simple post-processing step associated with an advanced sampling-based reliability analysis. It does not require any additional system response evaluations. In addition, the method provides information about the whole trend of the reliability sensitivity estimates in terms of the threshold levels. The approach is validated on two nonlinear structural models under stochastic ground excitation.