Multiobjective reliability-based design optimization approach using the gray system and evidence theory

Jiwei Qiu,Haisheng Luo 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

Aimed at the subjectivity of selecting the weight of each objective function in the process of multiobjective reliability-based design optimization (MRBDO), this study proposed a multiobjective weight quantitative analysis method by combining the gray incidence analysis method and evidence theory. This method derived the weight of each objective function from the uncertainty information of design variables, and effectively avoided the subjectivity of weight selection. First, the ideal attribute interval number and the interval number matrix of uncertain design variables were defined based on the gray system theory. On the basis of the definition of the information structure sequence, the gray incidence coefficient (GIC) matrix of measures with ideal attribute deviations was derived. Second, the basic probability assignment of each objective function and model under uncertainty variables was derived based on the DempsterShafer evidence theory. The Dempster-Shafer evidence synthesis rule was used to fuse the multisource evidence information to obtain the weight of each objective function. Then, an MRBDO problem was converted into a single-objective reliability-based design optimization (SRBDO) problem, which is relatively easier to address. Third, the performance measurement analysis (PMA) method was used to transform the reliability constraint into an optimized iterative process, and the MRBDO solution was obtained based on the MATLAB Optimization Toolbox and Symbol Toolbox. Finally, the accuracy and efficiency of the proposed method were verified through a numerical example and a small aeroengine gear reduction system.

Multi-objective optimization approach to reliability-based robust global optimization of electromagnetic device

Ren, Ziyan,Zhang, Dianhai,Koh, Chang Seop Emerald Group Publishing Limited 2013 Compel Vol.33 No.1

<B>Purpose</B> - The purpose of this paper is to propose a multi-objective optimization algorithm, which can improve both the performance robustness and the constraint feasibility when the uncertainty in design variables is considered. <B>Design/methodology/approach</B> - Multi-objective robust optimization by gradient index combined with the reliability-based design optimization (RBDO). <B>Findings</B> - It is shown that searching for the optimal design of the TEAM problem 22, which can minimize the magnetic stray field by keeping the target system energy (180?MJ) and improve the feasibility of superconductivity constraint (quenching condition), is possible by using the proposed method. <B>Originality/value</B> - RBDO method applied to the electromagnetic problem cooperated with the design sensitivity analysis by the finite element method.

신뢰성 해석을 이용한 차량 후드 보강재의 위상최적화

박재용(Jae-Yong Park),임민규(Min-Kyu Im),오영규(Young-Kyu Oh),박재용(Jae-Yong Park),한석영(Seog-Young Han) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.5

Reliability-based topology optimization (RBTO) is to get an optimal topology satisfying uncertainties of design variables. In this study, reliability-based topology optimization method is applied to the inner reinforcement of vehicle's hood based on BESO. A multi-objective topology optimization technique was implemented to obtain optimal topology of the inner reinforcement of the hood. considering the static stiffness of bending and torsion as well as natural frequency. Performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints. To evaluate the obtained optimal topology by RBTO, it is compared with that of DTO of the inner reinforcement of the hood. It is found that the more suitable topology is obtained through RBTO than DTO even though the final volume of RBTO is a little bit larger than that of DTO. From the result, multiobjective optimization technique based on the BESO can be applied very effectively in topology optimization for vehicle's hood reinforcement considering the static stiffness of bending and torsion as well as natural frequency.

RELIABILITY-BASED TOPOLOGY OPTIMIZATION BASED ON BIDIRECTIONAL EVOLUTIONARY STRUCTURAL OPTIMIZATION USING MULTI-OBJECTIVE SENSITIVITY NUMBERS

K.-H. CHO,박재용,S.-P. RYU,한석영 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.6

Reliability-based topology optimization (RBTO) is used to obtain an optimal topology satisfying given constraints, as well as to consider uncertainties in design variables. In this study, RBTO was applied to obtain an optimal topology for the inner reinforcement of a vehicle's hood based on bidirectional evolutionary structural optimization (BESO). A multi-objective topology optimization technique was implemented to obtain the optimal topology for two models with different curvatures while simultaneously considering the static stiffness of bending, torsion, and natural frequency. A performance measure approach (PMA) with probabilistic constraints formulated in terms of the reliability index was employed to evaluate the probabilistic constraints. The optimal topology obtained by RBTO was evaluated and compared to that obtained by deterministic topology optimization (DTO). A more suitable topology was obtained through RBTO than DTO even though the final volume obtained by RBTO was generally slightly greater than that obtained by DTO. The multiobjective optimization technique based on BESO can be applied very effectively with topology optimization for a vehicle's hood reinforcement.

Reliability-based Topology Optimization of Electro-Thermal-Compliant Mechanisms with a New Material Mixing Method

조강희,한석영,박재용,임민규 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Electro-thermal-compliant mechanisms are mechanisms onto which electric voltage is applied as input. This mechanism is based on the thermal expansion properties of the materials. This study considered all of the convection effects according to layouts produced after each topology optimization process. A new material mixing method based on bi-directional evolutionary structural optimization (BESO) was suggested to obtain optimal topologies for compliant mechanisms composed of two materials. Reliability-based topology optimization (RBTO) based on BESO was also applied to the topology optimizations of the mechanisms. Performance measurement approach (PMA), which estimates has probabilistic constraints that are formulated in terms of the reliability index, was adopted to evaluate the probabilistic constraints. The procedure has been tested in numerical applications, and the results were compared with those obtained by the level set and solid isotropic material with penalization (SIMP) methods for validation of the proposed approaches.

컴플라이언트 메커니즘의 신뢰성 기반 위상최적설계

임민규(Mingyu Im),박재용(Jae-Yong Park),한석영(Seog-Young Han) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.6

Electric-thermal-structural actuated compliant mechanisms are mechanisms onto which electric voltage drop is applied as input instead of force. This mechanism is based on thermal expansion of material while being heated. Compliant mechanisms are designed subjected to electric charge input using BESO(bi-directional evolutionary structural optimization) method. Reliability-based topology optimization (RBTO) is applied to the topology design of actuators. Performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints. In this study, BESO method is used to obtain optimal topology of compliant mechanisms from initial design domain. PMA approach is used to evaluate reliability index. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

전기구동 유연장치의 신뢰성 기반 구조최적화

김동연(Dongyeon Kim),임민규(Mingyu Im),유광선(Gwanseon Yoo),염영섭(Yeongseop Eom),박재용(Jaeyong Park),한석영(Seogyoung Han) 한국생산제조학회 2010 한국생산제조시스템학회 학술발표대회 논문집 Vol.2010 No.10

Electric-thermal-structural actuated compliant mechanisms are mechanisms onto which electric voltage drop is applied as input instead of force. This mechanism is based on thermal expansion of material while being heated. In this study, BESO method is used to obtain optimal topology of compliant mechanisms from initial design domain. PMA approach is used to evaluate reliability index. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

전기구동 유연장치의 신뢰성 기반 구조최적화

김동연(Dongyeon Kim),임민규(Mingyu Im),유광선(Gwanseon Yoo),염영섭(Yeongseop Eom),박재용(Jaeyong Park),한석영(Seogyoung Han) 한국생산제조학회 2010 한국공작기계학회 추계학술대회논문집 Vol.2010 No.-

Electric-thermal-structural actuated compliant mechanisms are mechanisms onto which electric voltage drop is applied as input instead of force. This mechanism is based on thermal expansion of material while being heated. In this study, BESO method is used to obtain optimal topology of compliant mechanisms from initial design domain. PMA approach is used to evaluate reliability index. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.