Updating Reliability of Monitored Nonlinear Structural Dynamic Systems using Real-time Data

Abstract

It is of great engineering interest to assess during the operation of a dynamic system whether it is expected to satisfy specified engineering performance objectives. To assess the system performance subjected to dynamic excitation, it is essential to evaluate the failure probability (or its complement, robust reliability) of the system. The word ‘failure’ is used to refer to unacceptable behavior or unsatisfactory performance of the system output. In this paper, we are interested in calculating the failure probability of any particular unobserved response of a structural system exceeding its threshold during the time when the system is subjected to dynamic excitation, based on real-time measurements of some output from the nonlinear structure (with or without corresponding input data). A similar problem was addressed in [1] but that work is only applicable for linear systems. A newly-developed approach based on stochastic simulation methods, which updates in real time the reliability of the nonlinear structural dynamic systems, is presented. The performance of the proposed approach is illustrated by numerical examples involving nonlinear dynamic systems.