Open Access

ARTICLE

Time-Variant Reliability-Based Multi-Objective Fuzzy Design Optimization for Anti-Roll Torsion Bar of EMU

by Pengpeng Zhi^1,2,3, Zhonglai Wang^1,2,*, Bingzhi Chen³, Ziqiang Sheng⁴

1 Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313001, China
2 School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
3 School of Mechanical Engineering, Dalian Jiaotong University, Dalian, 116028, China
4 Hefei CRRC Rolling Stock Co., Ltd., Hefei, 230012, China

* Corresponding Author: Zhonglai Wang. Email:

(This article belongs to the Special Issue: Computer-Aided Structural Integrity and Safety Assessment)

Computer Modeling in Engineering & Sciences 2022, 131(2), 1001-1022. https://doi.org/10.32604/cmes.2022.019835

Received 19 October 2021; Accepted 15 November 2021; Issue published 14 March 2022

Abstract

Although various types of anti-roll torsion bars have been developed to inhibit excessive roll angle of the electric multiple unit (EMU) car body, it is critical to ensure the reliability of structural design due to the complexity of the problems involving time and uncertainties. To address this issue, a multi-objective fuzzy design optimization model is constructed considering time-variant stiffness and strength reliability constraints for the anti-roll torsion bar. A hybrid optimization strategy combining the design of experiment (DoE) sampling and non-linear programming by quadratic lagrangian (NLPQL) is presented to deal with the design optimization model. To characterize the effect of time on the structural performance of the torsion bar, the continuous-time model combined with Ito lemma is proposed to establish the time-variant stiffness and strength reliability constraints. Fuzzy mathematics is employed to conduct uncertainty quantification for the design parameters of the torsion bar. A physical programming approach is used to improve the designer’s preference and to make the optimization results more consistent with engineering practices. Moreover, the effectiveness of the proposed method has been validated by comparing with current methods in a practical engineering case.

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