【作者】 李贵；

【导师】 柳玉起；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2008， 硕士

【摘要】 板料成形有限元模拟技术已经广泛运用到汽车覆盖件的冲压成形模拟中。目前板料成形数值模拟技术多用于单工序冲压成形模拟,而汽车覆盖件的成形是一个典型的多工序成形问题。虽然单工序模拟能够预测某工序工艺设计的缺陷,但是不能分析整个冲压工艺流程设计中出现的问题。因而对于汽车覆盖件需要一个基于实际工艺流程,面向全工序全流程的成形模拟系统。论文的研究得到国家自然科学基金项目“面向自主设计的汽车覆盖件成形性快速仿真及工艺优化技术研究”(No.50575080)和国家863计划项目“基于仿真的汽车零部件可成形性设计与工艺优化”(No. 2006AA04Z140)的资助。论文主要针对汽车覆盖件的成形工艺特点,开发了完整意义上的面向汽车覆盖件的全工序全流程成形模拟前置处理系统。论文根据汽车覆盖件的工艺特点对前置处理系统的需求和功能进行了详细分析,提出了以工序为核心的系统设计思想,并运用面向对象的程序设计方法对系统的总体框架、数据结构和数据流图进行分析和设计。在理论和系统设计的基础上,完成了面向汽车覆盖件的全工序成形模拟前置处理系统的开发,可以模拟重力、压边、成形、拉延、修边、翻边、卷边、回弹等汽车覆盖件成形过程中的所有工序。论文还对前处理系统的关键技术进行了研究,建立了基于工具圆角和网格加密级别的板料网格剖分准则;采用边界依赖法实现了工具单元法向量的自动调整;提出了虚拟板料的概念,改进了工具网格之间的自动测距算法,解决了全工序工具自动装配的难题,并实现了基于动画显示技术来检查全工序工具装配和干涉的功能;通过纯资源DLL和资源配置文件方式实现了系统的多语言版本。论文最后以实际的汽车地板、汽车前翼子板和空调翅片为例,采用本文开发的汽车覆盖件全工序成形模拟前处理系统对其进行有限元建模,验证了本系统能够为覆盖件的全工序全流程仿真提供真实准确的有限元模型和工艺参数。通过大量的实例测试表明,本系统达到了工业实用化水平,具有操作简单、功能强大、性能稳定的特点。现已在国内的多家企业中应用,并指导实际生产。更多还原

【Abstract】 Finite element simulation technology for sheet metal forming has been widely used in the forming of automobile panel in recent years. The numerical simulation technology for sheet metal forming is mostly used for single process simulation currently, while the simulation of automobile panel forming is a typical simulation for multi-operation. Although it can be predicted design flaws of the process by the simulation for single process, it cannot be forecasted the problems which are appeared in the entire stamping process. For the simulation for the automobile panel forming, a simulation system for complete process based on the actual process is required, which can truly simulate the whole processes for the automobile panel forming.This research is supported by NSF named:“The Independent Research of High-speed Simulation and Optimal Process Design aiming at the Formability of Automobile Panel”(NO.50575080) and National 863 Program:“The Formability and Optimal Process Design Based on the Simulation of Automobile Parts”(NO. 2006AA04Z140). This paper mainly focus on the characteristics of process for automobile panel forming, the author has developed a complete process simulation pre-process system, which is a significant entire process for the automobile panel forming.Based on the characteristics of automobile panel, the function and demands of the pre-process system is analyzed particularly, design idea of the system in which process is the core is presented, and the frame, data structure and data flow diagram of the system is studied on basis of Object-oriented design method. Based on the theory and the system design, a complete process simulation pre-process system for the automobile panel is developed, by which all processes of automobile panel can be simulated, which include gravity, closing, forming, drawing, trimming, flanging and springback.Some key technologies of the pre-process system are studied in this paper. The criteria of mesh generation of blank based on the fillet and mesh adaptive level is established. The automatic adjustment for the element normal vector based on the boundary-dependent algorithm is implemented. The concept of virtual blank is presented, and the automatic measure algorithm of tools elements is improved, which solves the problem of tools automatic assembly for complete process, further the tools assembly of the entire process and the interfere between the tools are checked by the animation, finally the multi-language version of the system is implemented by resource DLL and multi-language initial file.The actual stamping parts: car floor, car fender and air-condition fin is chose in this paper, it indicate that the pre-process system can provide accurate finite element model and processing parameters for the complete process simulation of automobile panel by the simulation of these parts. By testing numerous examples, it show that the pre-process system has reached the level of industrial utility, in which there is the characteristics of simple, powerful and stable performance. The system has been applied to many domestic enterprises and provides the guidance to actual production.更多还原