【作者】 冯浩；

【导师】 胡于进； 王学林；

【作者基本信息】 华中科技大学 ， 机械设计及理论， 2007， 硕士

【摘要】 随着科学技术和生产的迅速发展,有限元方法的运用越来越广泛,今天各工矿企业、设计、研究部门已普遍采用有限元方法进行生产过程的数值模拟、科研的数值试验和产品的优化设计。对产品进行有限元分析和优化可以校核产品的强度和刚度,并减小了重量,降低了成本。因此对产品进行有限元分析和优化具有重要意义。本文以某车载骨架结构为研究对象,先对车载骨架的拓扑结构进行了研究,利用梁单元建模进行了多方案的比较,得到了骨架比较合理的拓扑结构。然后利用有限元软件ANSYS建立了骨架结构的基于板壳单元的有限元模型,并对该骨架结构在四个典型载荷工况下的应力和变形进行了分析,并把有限元计算结果与试验结果进行了比较,同时还对骨架结构进行了模态分析。在综合分析汇总各种数据后,建立优化方程,选择骨架自重为目标函数,骨架结构的受载为约束条件,骨架的截面尺寸作为设计变量,进行了优化设计。最危险工况的计算结果表明骨架结构存在着缺陷,因此对骨架的局部结构进行了改进。通过对改进后骨架结构的计算结果与试验结果的比较,表明骨架结构的有限元模型及所加的边界条件是合理的。通过对骨架结构的优化,得到的优化结果达到了预期的目的,降低了骨架自重,又保证了骨架结构的强度和刚度。以上研究的结果为设计人员进行结构的改进和优化提供了技术依据。更多还原

【Abstract】 Following the fast development of technology and production, the application of the finite element method is more and more popular. Nowadays a lot of enterprises, design departments and research departments use finite element method to do some numerical simulation of production process, numerical experiment of research and optimization design of production. The finite element analysis and optimization of production can check the intensity and stiffness, and also reduce the cost. So the finite element analysis and optimization of production are very important.The thesis discusses the structure of a car-carried skeleton. First, the author does some research on the topological structure of the car-carried skeleton. After a few finite element models that built by beam element in ANSYS are compared, the author gets the more reasonable topological structure. When the building of the finite element model of the skeleton structure is finished in ANSYS software, the skeleton structure’s stress and deformation have been analyzed in four typical load cases based on the analysis of its working process. Then the computing result is compared with the experiment result, at the same time the modal analysis is done. After analyzing various kinds of data synthetically, the author sets up the equation of optimizing. Choose the weight of skeleton structure to be the goal function, the stress to be the restrain condition, and the sectional size of the frame to be design variable.The result in the most dangerous working status indicates that the intensity and stiffness of the skeleton structure is insufficient in the initial design, so the skeleton structure is improved. Then the author carries on the contrast to the result after improved and experiment result, and finds that the finite element model of the skeleton structure and boundary condition is reasonable. After the optimization, the author finds that the result is satisfying. The weight of the skeleton structure is reduced, at the same time the security of the skeleton is guaranteed. The result of research provides technical basis for the technicians to improve and optimize the skeleton structure.更多还原