An adaptive response surface method for reliability analysis of structures with multiple loading sequences

The response surface method (RSM) has been widely used in conjunction with non-linear finite element (NLFE) analysis to predict the reliability levels of structures that do not have explicit failure functions. In the present study, the solution of the reliability analysis initially diverged when the loading was applied in sequence in the NLFE analysis. A case study was performed in order to investigate the cause of the divergence. It was found that the divergence was mainly due to the non-smoothness of the response surface, and the quality and validity of the experimental design for numerical or NLFE analysis. An adaptive design approach is proposed to overcome these problems in reliability analysis, and several suggestions are made to improve the robustness of the RSM. Three numerical examples have been chosen to demonstrate the proposed method, which was verified by an independent Monte Carlo Simulation.