【作者】 张静；

【导师】 李柏林；

【作者基本信息】 西南交通大学 ， 机械制造及其自动化， 2008， 博士

【摘要】 随着科学技术的不断进步,机械系统越来越精密、复杂,其内部各组成部分之间的相互作用也日益明显。机械系统设计通常涉及到多学科、多目标、多约束、多个设计变量,使得机械系统的总体设计过程十分复杂。为挖掘设计潜力,提高设计质量,多学科设计优化(Multidisciplinary DesignOptimization,MDO)理论得到了极大重视。MDO通过充分利用各学科间相互作用所产生的协同效应,获得系统的整体最优解或工程满意解。目前,MDO已引起了国内外学术界的广泛关注,并在航空航天领域内取得了巨大成功,产生了巨大的效益。MDO在航空航天领域内的巨大成功也引起了其他工程设计领域的重视,MDO的应用范围已经拓展到了武器、汽车、计算机、通信、机械、医疗以及建筑等各个领域。引入MDO的思想到机构设计领域,研究了机构的设计模式。介绍了机构的串行、集成和MDO设计模式的定义,分析了机构设计模式的思想,建立了机构设计模式的优化模型,研究了机构设计模式的优缺点。归纳了MDO的耦合因素的类型,分析了影响MDO子系统之间耦合程度的一些主要因素,研究了耦合因素相互作用的机理,着重对交叉耦合因素进行深入研究分析,利用灵敏度计算结果,定义强弱耦合因素的概念,利用模糊数学信息,定义耦合因素的隶属度函数,提出强弱耦合因素的判定准则,构建了基于灵敏度分析的MDO解耦方法。分析了近似技术应用于MDO的重要性,阐述了MDO的局部近似技术和全局近似技术,归纳了试验设计方法。针对CO算法系统级的计算困难的难题,采用均匀设计方法,选取近似模型的样本点,利用Kriging近似技术,构造了系统级约束的近似优化模型,提出了改进的CO算法。分析了MDO系统的特点,提出了基于层次分析法(Analytic HierarchyProcess,AHP)确定各个子系统(学科)重要度的步骤,介绍了满意度和满意解的定义,列举了满意函数的常见分布类型及函数的选择问题,阐述了复杂系统MDO可行解的综合满意度的评价方法,建立了MDO可行解的满意度评价模型,构建了MDO可行解的评价函数,提出了MDO可行解的满意评价方法,从而指导进一步的设计。本文把MDO引入到机械设计领域,系统地研究了机构的设计模式、MDO的耦合复杂性难题、MDO算法和MDO可行解的评价方法等MDO关键技术,并将这些方法成功应用于机构系统设计与MDO经典工程算例。更多还原

【Abstract】 With the development of Science and Technology,mechanical systems are becoming more and more complex,the interaction between parts of them becomes increasingly obvious.The design of mechanical systems usually involves multidisciplinary、multi-objective、multi-constraint and multivariable.In order to improve design quality and develop design potential,the theory of multidisciplinary design optimization(MDO) is developed.It can be described as a methodology for the design of systems where the interaction between several disciplines must be considered,and where the designer is free to significantly affect the system performance in more than one discipline.At present,MDO has received much widely attention recently in academic circles,both at home and abroad.The success in the field of aerospace has been paid attention to by the researchers in non-aerospace fields.The yield of MDO application has been expanded to the field of weapon、automobile、computer、the mechanical design and other fields.The MDO idea is applied to the design of mechanism system.Three modes of mechanism design,such as serial design、integrated design and MDO mode are investigated systematically,including the definitions、the ideas and the optimization models.The merits and demerits of design mode are studied.Coupling complexity of MDO is studied.With the analyzing method of sensitivity information,coupling factors are researched.The factors of effecting coupling degree are analyzed.The conception of coupling strength is presented, the function of membership degree is defined with the method of fuzzy methematics,and the judgement criteria of coupling factors is proposed.Based on the conception and the judgement criteria,decoupling method of MDO is proprosed.The merit and demerit of collaborative optimization(CO) are analyzed.The local and global approximate technologies are introduced.The methods of experimental design are synthesized.According to the calculation problem of system level of CO,the uniform design is adopted to select sample points,the Kriging approximate technology is used to structure the system level constraints. The improved CO is proposed.In order to perfect the theory of MDO,the evaluation problem of feasible solution is researched.The characteristics of MDO systems are analyzed and summarized.The weights of disciplines are calculated. The definition of satisfactory solution is introduced.The satisfactory functions are enumerated.The satisfaction evaluation model of MDO feasible solution is established.The evaluation method of MDO feasible solution is proposed with offering guidance for further design.The dissertation introduces the idea of MDO to the field of mechanical design.The key technologies of MDO,such as design mode of the mechanism、MDO coupling complexity、MDO algorithms and evaluation method of MDO feasible solution,are studied,and all the research results has been successfully used in mechanism system and classical engineering example of MDO.更多还原