【作者】 温莉娜；

【导师】 王雷刚；

【作者基本信息】 江苏大学 ， 材料加工工程， 2007， 硕士

【摘要】 在车身覆盖件设计过程中，由于技术能力、开发周期和开发成本等诸多因素的限制，技术人员不可能仅依靠大量的传统试错分析对覆盖件的成形方案进行改进。因此有限元数值模拟技术逐渐成为提高车身开发水平不可缺少的重要工具。现有的覆盖件成形研究主要以验证是否能避免出现明显的产品缺陷为主，对于如何在设计阶段合理确定车身覆盖件各个参数等问题缺乏全面、系统的研究。因此研究拉深成形的变压边力技术，并且运用正交试验的方法，寻求适用于车身覆盖件成形过程的最优化参数组合，具有重要的工程意义和研究价谊。本文较系统的阐述和讨论了冲压成形仿真非线性有限元理论，包括材料模型、单元算法、接触及摩擦问题的处理等。讨论了冲压仿真有限元建模方法，并对仿真过程中关键问题做了较深入的研究，在此基础上对大型车身覆盖件的冲压过程进行了仿真。主要内容如下：1．系统阐述了车身覆盖件冲压成形仿真非线性有限元理论，讨论了仿真中冲压的三种材料模型，并在参考有关文献的基础上给出了Hill和Barlat模型的增量型弹塑性本构关系的显式表达及求解；阐述了适合于冲压仿真的BT壳单元理论和接触及摩擦问题的处理等。2．研究了车身覆盖件冲压成形仿真建模的关键问题，包括模具型面的设计、拉延筋的处理、压边圈的处理和压边力的计算等。3．详细介绍了利用DYNAFORM软件对江都汽车覆盖件厂生产的保险杠有限元建模过程。4．基于前面建立的保险杠有限元模型，运用正交实验的方法，对拉延筋深度、压边力大小、虚拟凸模冲压速度、凸凹模间隙四个参数进行了优化组合，同时具体分析了虚拟凸模速度和压边力对保险杠成形质量的影响。最后选取优化后的工艺参数进行了仿真，与实际生产的零件进行了对比分析，并提出了改进措施。更多还原

【Abstract】 Due to limitations of the technique, the lead time and the development cost in the design phase, an acceptable forming solution is not easy to obtain with a large number of trial-and-error runs. Numerical simulation technology, a quickly developing engineering analysis method, has laid a foundation for the automotive of the forming process design. It has been an indispensable tool to speed up the development of automotive.Most of the existing research on automotive panel forming is focused on verifying whether product defects appear. However, comprehensive and systematic work has rarely been done on how to improve the performance figures of automotive panel in the design phase. Optimization of funning process is a very difficulty problem due to design nonlinearity and huge computational cost of numerical simulations. Therefore, there is notable engineering significance and academic value to seek for a numerical simulation based optimization method for automotive panel forming process.In this paper, the non-linear explicit finite element theory is studied systematicly, which include material models, element algorithm and contact handling methods etc. The FE modeling methods of stamping simulation are investigated and a comparatively deep study on the key points of process. And on the basis of them, the forming simulation of large automotive panels is made and results analyzed.1. The non-linear finite element theory for automotive panel forming simulation is systematically expounded and discussed. Three usually used material models for stamping simulation are discussed and studied, and based on the reference of other research papers, the explicit description of Elastic-Plastic Materials for Hill’s and Barlat’s yield models are established. BT shell element theory and contact handling algorithm are also expounded in this paper.2. The key parameters in the simulation of stamp metal forming are studied, which include die-face, drawbead and blank-holder force.3. introduce the detailed processes of molding to a part of bumper base on DYNAFORM4. A part of bumper on automotive forming simulation is carried out in the way of orthogonal and the results are discussed, moreover, improved measure is put forward.更多还原