汽车顶盖冲压成形数值模拟及回弹优化研究

发布时间：2018-01-09 23:16

本文关键词：汽车顶盖冲压成形数值模拟及回弹优化研究　出处：《长春工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：近年来,汽车制造业已经逐渐成为国民经济的主要支柱产业,引领着国民经济的发展,与人们的日常生活息息相关。汽车覆盖件多采用高强度钢板,材料较薄、几何尺寸较大、表面成形质量要求较高。相比传统的试模法,有限元分析法可以有效预测成形缺陷的产生,并通过修改工艺参数进行成形优化。有利于减少试模、修模次数,缩短覆盖件的生产周期,提高产品的市场竞争力。本文应用DYNAFORM软件,对汽车顶盖进行了冲压成形仿真分析。主要进行了三维模型的建立、网格的划分与网格参数的控制、建立工艺补充面、确定材料类型与性能参数、估算坯料尺寸等数值模拟的前处理过程,并对比了无拉延筋、均匀分布拉延筋、分段变截面拉延筋三种不同拉延筋布置形式下覆盖件的成形特点,最终选取7段不同截面的拉延筋,得到较好成形质量。回弹作为板料冲压成形的一大主要缺陷,受到诸多因素的影响。本文主要以模具间隙、压边力、摩擦系数、虚拟冲压速度四个因素为代表,设计L16(45)正交试验,并分别以最小厚度、最大厚度、回弹量为指标,通过极差计算法与直观分析法的对比确定最优参数组合,通过方差分析法确定以上四因素对回弹的影响顺序。在所得最佳组合参数基础上,采用虚拟试模法对其进行回弹补偿,通过三次迭代最终将板料的回弹量控制在2mm以内,得到满足质量要求的产品,并对其进行实际生产。
[Abstract]:In recent years, the automobile manufacturing industry has gradually become the main pillar industry of the national economy, leading the development of the national economy, closely related to the daily life of people. Compared with the traditional die test method, the finite element analysis method can effectively predict the forming defects. By modifying the process parameters to optimize the forming process, it is helpful to reduce the number of die tests, repair the die, shorten the production cycle of the panels, and improve the market competitiveness of the products. This paper applies DYNAFORM software. In this paper, the stamping forming simulation analysis of the automobile roof is carried out. The 3D model is built, the mesh is divided and the mesh parameters are controlled, the process supplementary surface is established, and the material types and performance parameters are determined. The preprocessing process of numerical simulation such as blank size was estimated, and the forming characteristics of the panel were compared under three different types of drawing reinforcement arrangement: no drawing bars, uniform distribution of drawing bars and segmental variable cross-section drawing bars. Finally, 7 drawing bars with different sections are selected to get better forming quality. Springback is a major defect in sheet metal stamping, which is affected by many factors. In this paper, die clearance and blank holder force are the main factors. The four factors of friction coefficient and virtual stamping speed are represented by the design of L16C45) orthogonal test, and the minimum thickness, maximum thickness and springback are taken as the index respectively. The optimal parameter combination is determined by comparing the range calculation method with the visual analysis method, and the influence order of the above four factors on the springback is determined by the variance analysis method. On the basis of the best combination parameters obtained. The springback compensation is carried out by virtual test model method. Finally, the springback of sheet metal is controlled within 2mm through three iterations, and the products that meet the quality requirements are obtained, and the products are produced in practice.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG386

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