Extension of the DP-RS-Sim Hybrid Method to Time-Variant Structural Reliability Analysis

This paper presents the extension to time-variant reliability applications of a novel hybrid reliability method, namely the Design Point--Response Surface--Simulation (DP-RS-Sim) method. This method combines in an innovative way the design point search used in First- and Second-Order Reliability Methods (FORM/SORM) with the response surface method and appropriate simulation techniques. The proposed method is illustrated by using as benchmark example a nonlinear inelastic single-degree-of-freedom system subjected to Gaussian white noise base excitation from at rest initial conditions. The system is considered to fail when the roof displacement exceeds a predefined deterministic threshold. Estimates of the time-variant failure probability obtained through the DP-RS-Sim method are compared with the FORM-based mean out-crossing rate computations and crude Monte Carlo simulation results considered as reference solution. It is found that the DP-RS-Sim method can provide accurate time-variant failure probability estimates at low computational cost compared to other existing structural reliability methods and is therefore a promising method for large scale time-variant reliability applications