An integral method for Reliability-Based design Optimization

Abstract

In Reliability-Based design Optimization (RBDO), the aim is to develop an optimal design characterized by high reliability through fulfilling design requirements at the targeted probability threshold. The goal of reliability optimization is to obtain excellent algorithms by focusing on evaluation and optimization. In RBDO, due to the selection of evaluation methods and the problem of updating reliable point methods, it is often impossible to obtain accurate failure probability results with less computation, and the results are inaccurate, or the computation amount is increased. The integral-based reliability analysis method: Hyperspherical cap area integral method (HCAIM) can achieve an accuracy close to that of the MCS method while having a very low computational load, thus enabling the efficient and precise calculation of failure probabilities. Therefore, by introducing a reliability evaluation method based on Integral Method for Reliability Optimization (IMRO), as a decoupling method, high accuracy failure probability calculation results can be obtained with relatively small calculation amount, and then optimization results can be obtained by IMRO and sequence optimization methods. First, a reliability analysis example is utilized to demonstrate the accuracy of the reliability analysis part of IMRO. Then, a set of nonlinear challenges and diverse engineering case studies were utilized to assess the algorithm's performance. The calculation results after comparison prove that IMRO is more accurate in dealing with nonlinear problems and engineering examples, and can better meet the requirements.