【作者】 黄平华；

【导师】 何丹农；

【作者基本信息】 上海交通大学 ， 材料学， 2007， 硕士

【摘要】 随着全球汽车行业的竞争日趋激烈,我国汽车工业面临着严峻的挑战。当前最紧迫的任务是:在引进国外整套模具的基础上,如何进行消化吸收从而建立具有自主知识产权和较强市场竞争力的企业核心技术和开发平台,实现自主创新和发展,迅速摆脱我国汽车业在技术上受制于国外企业和缺乏创新能力的局面。覆盖件模具设计制造周期的长短和质量,对新车型的开发周期、汽车产品的质量和竞争力有着直接影响。本文针对某车型典型的覆盖件――行李箱盖内覆盖件,采用CAD/CAE/CAM技术,对冲压成形模具的型面CAD逆向建模技术以及冲压成形有限元仿真模拟技术进行了系统深入的研究,为缩短新型汽车研发周期、提高汽车覆盖件质量,降低成本提供技术上的支持。为了建立覆盖件冲压成形仿真系统,本文首先在逆向工程软件IMAGEWARE中对覆盖件模具的点云进行了点云对齐、点云精简、点云去噪等数据预处理工作,在分析覆盖件形状特征的基础上通过正逆向结合的方法构建了模具的型面。接着把CAD模型导入DYNAFORM软件中,根据覆盖件拉深成形以及所用板料的特点,在建立覆盖件拉深仿真模拟系统时,通过比较各种不同本构关系以及壳单元类型的基础上选用了Balart三参数屈服模型和Belytschko-Tsay壳单元。参考实际工艺条件利用建立的覆盖件拉深仿真模拟系统进行有限元分析计算,计算结果与实际非常吻合,很好的反映了该覆盖件在拉深成形过程中的破裂和起皱缺陷的位置和程度,揭示了缺陷发生的根本原因,从而提出了消除或者改善这些缺陷的措施。通过覆盖件拉深成形的仿真分析,优化了拉深工艺方案,较好的消除了破裂以及起皱现象。更多还原

【Abstract】 With the drastically competition between the global carmaker, the auto-industry of our country faces serious challenge. It is urgent for our country how to absorb the advanced technology in base of introducing a series of stamping moulds to establish key technology with independent knowledge property right and then break away the dependence of foreign enterprises and raise the innovative ability.The design and manufacturing time and quality of panel dies have direct effect on the development period of new cars, their quality and competitive capability. This paper focused on comprehensive study of surface CAD Reverse Engineering (RE) modeling and Finite Element Analysis (FEA) for forming process of automobile back trunk inner panel in order to shorten the period of research and development for modern car, improve the quality of body cover panel and reduce the cost.To create FEA model for cover panel forming process, firstly, reducing and noise eliminating process were applied in the original cloud of cover panel with the IMAGEWARE software. Then, the CAD model of the surface was created through reverse and obverse method based on the analysis of character of the cover panel. Thirdly, the CAD model was imported into the DYNAFORM software. Barlat 3-parameter yield model and Belytschko-Tsay shell element were used for FE simulation according to character of cover panel forming process and materials. The FEA simulation system of stamping process was built and the simulation result was consistent with practice. The producing mechanism and corresponding countermeasure of the defect such as break and wrinkle were revealed. The optimized parameters for cover panel forming process were obtained through FE simulation.更多还原