【作者】 张勇；

【导师】 徐宗俊； 张力；

【作者基本信息】 重庆大学 ， 机械制造及其自动化， 2005， 硕士

【摘要】 由于汽车整车装配是个复杂的组合,要使整车具有良好的性能和价格优势,就必须首先对汽车组件及其零件进行合理设计和优化。日本、欧美等国家在新车开发中普遍采用计算机辅助工程分析、虚拟实验、动态测试等现代技术,使设计制造的产品在性能方面有明显优势;而我国的一些汽车制造企业在技术上大都凭借经验、仿造及局部修改等方法进行设计,对汽车组件及零件的性能分析、模拟仿真与测试,还开展的不够普及和深入。本文把计算机辅助工程建模仿真技术应用到汽车组件的结构设计及校核的实例领域,通过数值分析和有限元建模方法,为汽车重要组件产品建立了合适的数字模型,从而预估产品的强度负荷及寿命水平等,提高其设计效率和科学性。研究内容中,结合现代数值分析技术的发展,讨论了有限元模型的构建原则和网格形成技术特点,并综合分析了有限元分析的误差影响因素;针对组件结构,比较详尽的阐述了组件有限元的特征建模方法,提出了基于组合结构的有限元方法概念,讨论了多物理模型接触非线性、多点约束特征、多件耦合传热边界等复杂算法问题;在组件特征算法的基础上,针对汽车部分组件的工程应用实例,进行了发动机活塞组的接触非线性问题求解,以及活塞组多件传热模型的研究;运用多点约束特征,计算了汽车车架的静应力和结构模态;以疲劳为基础分析了汽车前轴的抗疲劳特性;在组件有限元模型数值结果分析中,提出了实用的数据后处理评价方法;同时运用实验仪器或实验系统,参照有关法规及标准,局部验证了汽车组件性能的数值模拟可靠性,并提出了有关组件结构设计的改进方案。通过理论研究和工程实例的应用,体现出计算机辅助工程技术在产品设计初期的优越性:即一方面建立一种基本的计算机分析模型,对其进行仿真模拟,从而指导产品设计;另一方面以此为汽车结构的虚拟分析平台提供一些规范化或经验性的建模参考,同时也为提高企业在技术上的自主开发及创新能力而奠定基础。更多还原

【Abstract】 Due to the complexity of automobile assembly, the advantage of better performance and lower price depends on the reasonable and optimizing design to its subassemblies and components. The modern technologies of CAE, virtual and dynamic test etc, which are adopted to the development of new types of vehicle in Japanese, Europe and America, have made more progress for manufacture products. But few technologies of above for vehicle design, are exploited in our China, which are instead of experiences, copies and modifications etc. The simulation method of CAE will be applied to the design and check field of automobile subassembly structures in this article. Through the numeric analysis and FEM, the strength and fatigue life level etc, are estimated for the subassembly. In research contents, with the development of numeric analysis considered, discuss the finite element modeling principles, mesh features and influencing factors of error; for subassembly model, put forward the concept of finite element method based on assembled structures, such as the phenomena of nonlinear contact, MPC constrain, coupled boundary of heat transfer. In the engineering application of vehicle subassembly, build the nonlinear contact and heat transfer model of motor piston, and the MPC feature model of vehicle frame for its stress and modal; analyze the fatigue character of axle beam through fatigue theory; in the FEM result, find out a practical evaluation method for the result data; at last, with some related regulations and criterions, consulting experiment instruments and systems, partly verify the validities of numeric simulation to subassembly performance, and then give some improved schemes for original component designs. The theory research and engineering application, show the superiority of CAE to product design: one is instructing the design through the computer analysis model; the other is to provide a modeling reference to virtual platform, and to promote the self-exploitation ability for the enterprise.更多还原