Open Access

ARTICLE

A New Multi-objective Reliability-based Robust Design Optimization Method

by Zichun Yang¹, Maolin Peng¹, Yueyun Cao¹, Lei Zhang¹

1 Naval University of Engineering, China 430033.
2 Center for Aerospace Research & Education, University of California, Irvine. Visiting professor.
3 Naval Equipment Technology Institute, Qingdao 260012, China.
4 Corresponding author. Email: pmaolin999@163.com

Computer Modeling in Engineering & Sciences 2014, 98(4), 409-442. https://doi.org/10.3970/cmes.2014.098.409

Abstract

A new multi-objective reliability-based robust design optimization (M ORBRDO) model is proposed which integrats the multi-objective robustness, the reliability sensitivity robustness and the six sigma robustness design idea. The pure-quadratic polynomial functions are adopted to fit the performance objective functions (POF) and the ultimate limited state functions (ULSF) of the structure. Based on the ULSF and the checking point method, the equations of the first order reliability index are calculated. The mapping transformation method is employed when the non-normal distribution variables are included. According to the POF and the Taylor series expansion method, the equations of mean value and standard deviation of the performance objectives are deduced. In order to improve the efficiency of MORBRDO, a new reliability based design optimization strategy is proposed. The new strategy does not update the ULSF in the sub-cycle of reliability calculation process, so that the computational work is reduced remarkably. Then, the optimum design was obtained with the sequential quadratic programming method. Finally, three engineering projects, a I-beam structure, a pressure vessel and the turbine blade model lines are introduced to redesign their sizes by the new MORBRDO methodology proposed in this paper. The results prove that the new MORBRDO model and methods are correct, feasible and efficient, so it is valuable theoretically and applicative in engineering.

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Keywords

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