Novel decoupled framework for reliability-based design optimization of structures using a robust shifting technique  

作　　者：Mohammad Reza GHASEMI Charles V. CAMP Babak DIZANGIAN 

机构地区：[1]Department of Civil Engineering, University of Sistan and Baluchestan, Zahedan 9816745565, Iran [2]Department of Civil Engineering, The University of Memphis, Memphis, TN 38152, USA [3]Department of Civil Engineering, Velayat University, Iranshahr 9911131311, Iran

出　　处：《Frontiers of Structural and Civil Engineering》2019年第4期800-820,共21页结构与土木工程前沿（英文版）

摘　　要：In a reliability-based design optimization (RBDO), computation of the failure probability (Pf) at all design points through the process may suitably be avoided at the early stages. Thus, to reduce extensive computations of RBDO, one could decouple the optimization and reliability analysis. The present work proposes a new methodology for such a decoupled approach that separates optimization and reliability analysis into two procedures which significantly improve the computational efficiency of the RBDO. This technique is based on the probabilistic sensitivity approach (PSA) on the shifted probability density function. Stochastic variables are separated into two groups of desired and non-desired variables. The three-phase procedure may be summarized as: Phase 1, apply deterministic design optimization based on mean values of random variables;Phase 2, move designs toward a reliable space using PSA and finding a primary reliable optimum point;Phase 3, applying an intelligent self-adaptive procedure based on cubic B-spline interpolation functions until the targeted failure probability is reached. An improved response surface method is used for computation of failure probability. The proposed RBDO approach could significantly reduce the number of analyses required to less than 10% of conventional methods. The computational efficacy of this approach is demonstrated by solving four benchmark truss design problems published in the structural optimization literature.

关 键 词：reliability-based design optimization TRUSSES sensitivity analysis SHIFTING TECHNIQUE CUBIC B-SPLINES RESPONSE surface method 

分 类 号：X[环境科学与工程]