RESPONSE-SURFACE METHOD FOR TIME-VARIANT RELIABILITY-ANALYSIS

A method is presented to efficiently approximate the failure probabili ty of structures subjected to time-variant loads, where the system of loads and structure may have uncertain parameters. The method uses res ponse surface methodology in conjunction with the fast integration tec hnique suggested by Wen and Chen, to provide a limit-state formulation that is computationally simple to solve based on a small number of re sponse time histories. The system reliability may then be quickly comp uted by first-order reliability method (FORM)/second-order reliability method (SORM) or Monte Carlo simulation. Sensitivity analysis is perf ormed to determine the effect on the failure probability of changes to the system parameters, which can be important when determining whethe r uncertainty in a given system parameter is significant. An empirical measure of the accuracy of the response surface approximation is pres ented.