【作者】 赵振；

【导师】 张树有；

【作者基本信息】 浙江大学 ， 机械设计及理论， 2012， 博士

【摘要】 随着产品规模及复杂度增加,越来越呈现出多领域、强耦合的特点,产品开发难度大、周期长、成本高,整个产品的设计工作已经难以由设计者单独来完成,而是变成一个具备多学科性和群体协作性的工作。特别是瞬态多场耦合问题,它的物理场在时域上动态变化,且场间耦合程度高。随着数字化设计技术发展,产生了大量的仿真分析工具,但大多数分析工具只针对单学科问题,且各分析工具是异构的,不具有标准性与开放性,为数不多的多学科分析工具一般是针对特定的耦合问题,或者是通过对各学科分析工具简单调用实现松散耦合的多学科问题优化设计,对于异构仿真系统强耦合问题难以直接进行分析,因此有必要对异构仿真系统耦合瞬态场分析技术进行研究。本文在对产品数字化仿真技术、多场耦合分析技术及协同仿真技术研究现状进行总结分析的基础上,对异构仿真系统耦合瞬态场分析模型、电磁-机械耦合分析中瞬态电磁场分步回归求解技术、考虑电磁-机械耦合系统柔性可动部件耦合振动的冲击副模型、以及自适应步长的耦合瞬态场顺序耦合分析技术进行了研究,并结合工程需要,对相关问题进行了仿真分析,取得了较好的效果。全文的组织结构为：第1章概述了产品数字仿真分析技术、多场耦合求解技术及协同仿真技术的研究现状,对相关理论、技术进行了分析与归纳,指出了目前异构仿真系统瞬态场仿真分析技术研究中的不足,给出了论文的主要研究内容与组织结构。第2章提出了异构仿真系统耦合瞬态场分析模型。对异构仿真系统稳态场耦合与瞬态场耦合问题求解机制进行了研究,提出了异构仿真系统耦合瞬态场分析模型,对耦合瞬态场问题求解时的非平衡载荷残差,各瞬态进行准稳态分析的临界步长及传统方法求解瞬态场耦合问题的利弊进行分析,最后给出了异构仿真系统耦合瞬态场分析的信息交互机制、仿真机制及求解步骤,并将该模型应用于低压断路器延时脱扣分析,取得了理想的结果。第3章提出了电磁-机械耦合分析中瞬态电磁场分步回归求解技术。定义断路器最小分断单元与最小分断单元生命周期,利用高斯核函数构建分断电流与自变量拟线性映射,采用偏最小二乘回归方法对最小分断单元设计变量进行初级回归,并结合仿真分析技术反求最小分断单元生命周期内状态变量,构建分断电流关于状态变量二次回归预测模型。针对分断仿真所处不同阶段,采用不同电流回归模型作为源电流,基于有限元技术求解断路器瞬态电磁场分布。将该技术在低压断路器分断仿真的电磁场分析中应用,有效求解分断过程时变电磁场。第4章提出了考虑电磁-机械耦合系统柔性可动部件耦合振动的冲击副模型。考虑复杂产品电磁-机械耦合分析中柔性部件引起的耦合振动现象,以电梯产品为例,针对电梯轿厢系统与导轨耦合振动问题,建立刚性导轮-柔性导轨的Dubowsky二状态间隙模型,代替传统电梯水平振动特性分析中的质量-弹簧-阻尼模型。采用有限单元法生成导轨模态中性文件,并根据模态叠加法原理对导轨模态中性文件进行优化。分别建立轿厢与导轨振动分析数学模型,基于两者几何相容性与作用力平衡条件,给出导轨与导轮位移、速度、激振力耦合关系。该模型在电梯水平振动特性仿真分析中得到应用。第5章提出了自适应步长的耦合瞬态场顺序耦合分析技术。通过提取迭代节点耦合状态变量数值解,构造基于拉格朗日基函数的步长调整判别式,建立步长自适应调整策略,根据耦合状态变量数值曲线波动性动态调整瞬态步步长,解决复杂机械产品电磁-机械耦合问题求解时,固定瞬态步长难以在求解精度及效率间取得平衡的问题。对于包含多个耦合状态变量的复杂瞬态场耦合问题,建立多状态变量问题数据交互及步长自适应调整机制,减少冗余的数据交互及求导工作,将该技术应用于低压断路器短路分断仿真中,实现对分断过程电磁-机械耦合问题仿真分析。第6章结合工程实际需求,将异构仿真系统耦合瞬态场分析各关键技术在低压塑壳断路器分断仿真及高速电梯水平振动特性分析中进行了应用,并与实验结果进行对比,在实践中证明本文方法的正确性与可行性。第7章总结了本文的研究内容与成果,并对进一步研究工作进行了展望。更多还原

【Abstract】 As the size and complexity of products increases, it presents the characteristics of multi-field and strong coupling, the development of products becomes difficult, long cycle and high cost, it is unable to complete the design by single designer, the development of products has become a group work with multi-disciplinary and collaborate, especially the transient multi-field coupling problems, whose physical fields are strong coupled, and changing in the time domain. As the development of digital design techniques, there are a large number of excellent single, multi-disciplinary simulation tools, but most of them do not have the standard and openness, it is difficult to directly analyze this problem, so it is necessary to study the co-simulation technique of transient coupled field in heterogeneous simulation environment. In this paper, on the basis of analysis of digital product simulation technique, multi-field coupling analysis technique and co-simulation technology, some key simulation techniques of transient physical coupled field in heterogeneous simulation system were studied, they are: simulation model of transient physical coupled fields of heterogeneous simulation system, transient electromagnetic fields stepwise regression analysis technique of electromagnetic-mechanical coupling problem, the rigid-flexible coupled contact-impact model of flexible movement components of electromagnetic-mechanical coupling problem, and analysis technique of step self-adaptive sequential-interaction of transient coupled multi-field, and according to the engineering problem, simulated and analyzed some problems, the result shows that the simulation technique is effective.The organizational structure of the paper is as follow:In chapter 1, overviewed the study status of digital simulation technique, multi-field coupling analysis technique and co-simulation technique, analyzed and inducted related theory and technique, and pointed out the lack of current study of the simulation technique of transient coupled field in heterogeneous simulation system, given the paper’s study content and organizational structure.In chapter 2, the simulation model of transient physical coupled fields of heterogeneous simulation system was proposed. The solution mechanism of transient physical field coupled problem and the steady-state physical coupled problem was studied, and the residual unbalanced load of the solution of transient physical field coupled problem, the critical step of every transient step was also be studied. At last, the information exchange mechanism, the simulaton mechanism, and the solution steps of transient physical coupled fields of heterogeneous simulation system were given, and the model was applied into the analysis of short-circuit trip delay analysis of low-voltage circuit breaker, and achieved the expected results.In chapter 3, transient electromagnetic fields stepwise regression analysis technique of electromagnetic-mechanical coupling problem was proposed. Minimum breaking unit and life cycle of minimum breaking unit was defined, the quasilinear mapping of breaking current and design variables was built by the Gaussian kernel function, and initial regressed on the design variables of minimum breaking unit by the partial least square regression method, and reversed the state variables according to the life cycle of minimum breaking unit by simulation. According to different periods of break, using different regression models to prived the source current, to solve the transient electromagnetic field distribution of MCCB. This technique was applied into the breaking simulation of a model of MCCB, and solved the problem successfully.In chapter 4, a rigid-flexible coupled contact-impact model of flexible movement components of electromagnetic-mechanical coupling problem was proposed. In order to take the interaction of vibration subsystem into account, the guide rail was took as flexible body, and every pair of guide roller and rail was took as the Dubowsky’s contact model, to substitute the mass-spring-dashpot system in tradition model. The vibration equations of elevator car and guide rail was established, and the relations of variables such as displacement, velocity and excitation force between guide rollers and rails were given by satisfying the geometry compatibility and force equilibrium condition. The model was successfully applied into the horizontal vibration analysis of a model of high-speed elevator.In chapter 5, the analysis technique of step self-adaptive sequential-interaction of transient coupled multi-field was proposed. A three-points derivation equation was established based on interpolation polynomial of Lagrange by extracting the numerical solution of state variables of every iteration nodes, the rule for step adaptive was also established. According to the slope of the curve of coupling variables, the iteration steps can adjusted adaptively. For the problems that have more than one couple of coupling variables, the rule of date exchange and step adjustment of multi-state variables problem was established. This method was applied into the electromagnetic-dynamic interaction problem of low-voltage circuit breaker short-circuit breaking, and proved the feasibility of this method.In chapter 6, according to the engineering problem, the technique was applied into short-circuit breaking simulation of MCCB and horizontal vibration simulation of elevator, the results were analyzed and compared with the experimental results, the technique was proved correct and feasible in practice.In chapter 7, summarized the contents and results of the study, and prospected the further work.更多还原