A novel probabilistic feasible region method for reliability-based design optimization with varying standard deviation

An effective method for reliability-based design optimization (RBDO) problems taking uncertainties into account is the probabilistic feasible region (PFR) approach. The PFR approach is built around the fixed nature of the standard deviation in general RBDO problems. Therefore, the accuracy of the PFR approach will be affected when dealing with RBDO problems with varying standard deviation. To improve the accuracy of PFR method in solving the RBDO problems with varying standard deviation, a novel probabilistic feasible region strategy considering varying standard deviations (PFR-vstd) approach is suggested in this paper. In place of the initial probabilistic feasible region in standard normal space, a new probabilistic feasible region is established in original design space in this novel approach. The results of four applications demonstrate the high accuracy and sufficient efficiency of PFR-vstd method. The findings demonstrate that PFR-vstd method is capable of accurately resolving RBDO problems with varying standard deviation.