설계변수의 변동 불확실성을 고려한 신뢰성기반 최적설계

Abstract

Although many reliability analysis and reliability-based design optimization (RBDO) methods have been developed to estimate reliability of a system, many researches assume the uncertainty of the design variable to be constant. In practice, because uncertainty of design variable varies with changing values of the design variable, the reliability of the optimum design is inaccurate with this assumption. Therefore the uncertainty should be considered as variable uncertainty in RBDO. In this paper, we propose a method of RBDO considering variable uncertainty. The variable uncertainty can modify the uncertainty for each design point resulting in accurate reliability estimation. Finally, a notable optimum design is obtained using the proposed method with variable uncertainty. A mathematical example is illustrated to verify the proposed method.