轿车覆盖件的成形分析和数值模拟

发布时间：2018-11-28 15:59

【摘要】：随着世界经济的不断发展,汽车工业已经被一些工业发达的国家认定为国民经济的支柱型产业。经济全球化和世界经济市场的一体化的发展,刺激了汽车企业之间的竞争,如何提高产品零件的质量,缩短生产制造的周期,成为能否在竞争中获胜的关键。经过大量的研究和实践证明,CAE技术的应用使得轿车覆盖件模具生产过程中修模、试模的次数得到了极大的减少,加工制造周期得到了缩短,减少了工人的工作量,降低了生产成本。同时,CAE技术的应用可以提前预测冲压零件的缺陷,帮助设计人员对冲压工艺进行优化,得到更高质量的产品零件。冲压成形过程是一个大挠度、大位移的复杂变形过程,影响零件成形的因素有很多,传统的试错法盲目性很大,效率较低,为了得到最佳的工艺参数组合,就需要对冲压成形工艺进行更深入的研究。本文首先介绍了轿车覆盖件有限元仿真分析研究进展和冲压成形有限元基本理论。然后以某车型后背门内板为例,首先对其进行了拉延冲压成形的工艺设计,使用UG软件建立了拉延模具的三维模型,然后利用DYNAFORM模拟软件对成形过程进行仿真模拟；其次,设计正交试验,以压边力、摩擦系数、冲压速度和模具间隙为试验因素,以最大变薄率和最大增厚率为评价指标,经过分析得到了各因素对评价指标的影响次序,以及评价指标进行优化后的工艺参数方案；然后,以正交试验为基础,运用综合加权评分法和灰度关联度法对后背门内板的拉延成形工艺参数进行优化,随后将三种优化方法得到的成形结果进行对比,可以发现进行了灰度关联优化的成形方案的零件,其成形最充分,成形质量最高；最后对三种方法优化后的成形零件进行回弹有限元模拟,观察三种结果可以发现,灰度关联度优化的回弹小的区域面积更大,产品质量最高,然后对其进行回弹补偿再次进行回弹计算,得到了符合要求的产品零件。综上可以发现,灰度关联度优化后的结果具有更高的成形质量,通过灰度关联优化可以得到最佳工艺参数方案,并可以作为现场调试阶段的工艺参数。本文通过对后背门内板冲压成形工艺参数方案的优化研究,为板料冲压成形CAE分析最佳工艺参数方案的确定提供了合理的参考。
[Abstract]:With the development of world economy, automobile industry has been regarded as the pillar industry of national economy by some developed countries. With the development of economic globalization and the integration of the world economic market, the competition among automobile enterprises has been stimulated. How to improve the quality of product parts and shorten the cycle of production and manufacture has become the key to win the competition. Through a lot of research and practice, it has been proved that the application of CAE technology can greatly reduce the number of mould test, shorten the manufacturing cycle and reduce the workload of workers. The cost of production has been reduced. At the same time, the application of CAE technology can predict the defects of stamping parts in advance, help designers to optimize the stamping process and get higher quality parts. The stamping process is a complex deformation process with large deflection and large displacement. There are many factors that affect the forming of parts. The traditional trial and error method is very blind and inefficient. In order to obtain the best combination of process parameters, It is necessary to study the stamping process more deeply. This paper first introduces the research progress of finite element simulation analysis of car panel and the basic theory of stamping forming finite element. Then taking the rear door inner plate of a vehicle as an example, the process design of drawing stamping forming is carried out first, the three-dimensional model of drawing die is established by using UG software, and then the forming process is simulated by DYNAFORM simulation software. Secondly, the orthogonal test was designed, with the blank holder force, friction coefficient, stamping speed and die clearance as the test factors, the maximum thinning rate and the maximum thickening rate as the evaluation index, and the order of influence of each factor on the evaluation index was obtained through the analysis. And the process parameter scheme after the evaluation index is optimized; Then, on the basis of orthogonal test, the drawing process parameters of the internal plate of the back are optimized by using the comprehensive weighted scoring method and the gray correlation degree method, and then the results obtained by the three optimization methods are compared. It can be found that the parts of the forming scheme with gray correlation optimization are the most fully formed and the forming quality is the highest. Finally, the springback finite element simulation of three kinds of optimized forming parts is carried out. After observing the three kinds of results, it can be found that the area with small springback is larger and the product quality is the highest in the optimization of gray correlation degree. Then the springback compensation is used to calculate the springback again, and the parts that meet the requirements are obtained. In summary, it can be found that the optimized result of gray correlation degree has higher forming quality, and the optimal process parameter scheme can be obtained by gray correlation optimization, and it can be used as the process parameter in the field debugging stage. In this paper, the optimization of the process parameters for the stamping process of the back door inner plate is studied, which provides a reasonable reference for the determination of the best process parameter scheme for the CAE analysis of sheet metal stamping.
【学位授予单位】：安徽工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U466;TG386

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