汽车后地板纵梁前段冲压数值模拟及回弹控制研究

发布时间：2018-04-30 08:28

本文选题：板料成形 + 数值模拟　；参考：《合肥工业大学》2017年硕士论文

【摘要】：随着我国汽车行业的飞速发展,CAE计算机辅助模拟技术在汽车零部件的设计和生产中得到了广泛应用。其中基于有限元理论的板料冲压数值模拟技术是汽车覆盖件冲压成形模具设计的重要辅助工具。板料冲压成形数值模拟技术能有效地预测出板料在成形时出现的起皱、开裂、回弹、冲击线和滑移线等缺陷,而这些缺陷则可通过相应的工艺改进和参数优化等方法来改善或消除。在实际生产中CAE分析技术的应用可大大缩短模具的开发周期,减少试模次数,提高生产效率,降低生产成本。本文以汽车后地板纵梁件前段为研究对象,对其进行了有限元数值模拟仿真分析。针对模拟结果产生的起皱、开裂和回弹等缺陷,进行了工艺方案优化和相关参数优化,改进了回弹的控制方法,从而到达了符合生产要求的目的。首先,本文介绍了汽车板料成形数值模拟技术应用范围以及国内外的发展状况。根据课题需要,选择了Dynaform,Autoform软件作为后地板纵梁件前段的有限元分析软件,Design-export软件作为实验设计和参数优化软件,Matlab软件作为遗传算法优化软件。其次通过对软件功能的学习研究,建立了后地板纵梁件前段的有限元模型,进行了相应的数值模拟分析研究,分析出零件冲压后可能存在的缺陷。再根据冲压结果,对后地板纵梁件前段进行了工艺改进和有限元分析。结果表明,通过优化圆角和增加拉延筋可明显改善冲压成形时所产生的缺陷。在此基础上进一步进行了优化,利用拉丁方试验和遗传算法对压边力、拉延筋圆角半径、拉延筋高和摩擦系数等四个工艺参数进行了优化,获得了有效控制冲压缺陷的工艺参数组合。最后,在回弹控制方法研究的基础上对后地板纵梁件的回弹进行了模拟分析。分析发现在最后整形工序后其零件的一边缘区域回弹过大,为此采用了沿法线方向对该边缘区域进行适当补偿的方法,从而最终将回弹误差控制在合理的范围内。本研究为企业生产工艺的改进提供了有益参考。
[Abstract]:With the rapid development of automobile industry in China, CAE computer aided simulation technology has been widely used in the design and production of automobile parts. The numerical simulation technology of sheet metal stamping based on finite element theory is an important assistant tool for stamping die design of automobile panel. The numerical simulation technology of sheet metal forming can effectively predict the defects such as wrinkling, cracking, springback, impact line and slip line, etc. These defects can be improved or eliminated by corresponding process improvement and parameter optimization. The application of CAE analysis technology in actual production can greatly shorten the development period of die, reduce the number of mold tests, improve production efficiency and reduce production cost. In this paper, the front section of the rear floor longitudinal beam is taken as the research object, and the finite element numerical simulation analysis is carried out. Aiming at the wrinkling, cracking and springback of simulation results, the optimization of process scheme and related parameters is carried out, and the control method of springback is improved to meet the requirements of production. Firstly, this paper introduces the application of numerical simulation technology of automobile sheet metal forming and its development at home and abroad. According to the need of the project, the software of Dynaform-Autoform is chosen as the finite element analysis software of the front section of the longitudinal beam of the rear floor, and the software of finite element analysis (FEA) is chosen as the software of experimental design and parameter optimization. The Matlab software is used as the optimization software of genetic algorithm. Secondly, by studying the function of the software, the finite element model of the front section of the back floor longitudinal beam is established, and the corresponding numerical simulation analysis is carried out, and the possible defects of the parts after stamping are analyzed. According to the stamping results, the process improvement and finite element analysis of the front section of the rear floor longitudinal beam are carried out. The results show that the defects in stamping can be improved obviously by optimizing the fillet and increasing the drawing bar. On the basis of this, the four parameters of blank holder force, circle radius of drawing bar, height of drawing bar and friction coefficient are optimized by Latin square test and genetic algorithm. A combination of process parameters is obtained to control stamping defects effectively. Finally, based on the research of springback control method, the springback of the rear floor longitudinal beam is simulated and analyzed. It is found that the springback of an edge area of the part is too large after the final shaping process, so the method of compensating the edge region along the normal direction is adopted to control the springback error within a reasonable range. This research has provided the beneficial reference for the enterprise production craft improvement.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U466;TG386

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