【作者】 闫卫京；

【导师】 柳玉起；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2011， 硕士

【摘要】 汽车覆盖件结构复杂,外形轮廓尺寸大,一般都包含复杂的局部翻边形状,成形质量高求高。在产品设计阶段,传统方法主要根据经验或简单的理论方法设计产品形状,对工程技术人员要求很高。随着科技的进步和计算机技术的发展,有限元模拟技术的产生可以帮助设计人员在产品设计阶段就考虑影响产品可制造性的各种因素,在很短的时间内,得出比较精确的结果,在很大程度上节省了产品开发成本,缩短产品开发周期。论文的研究得到国家数控重大专项项目“C级轿车覆盖件整体侧围、翼子板和新型环保材料内饰件冲压成形模具”(No.2009ZX04013-031)和国家自然科学基金“复杂汽车结构件多工位级进模条料设计的快速仿真模型与关键算法研究”(No.50905067)的资助。论文采用CAA二次开发技术,设计开发了基于CATIA平台的汽车覆盖件产品设计可成形性同步仿真系统BEW (Blank Estimation Wizard)。该系统利用CATIA发布(publication)功能,实现CAD与CAE模型的同步更新,减少了产品设计初期CAE反复建模时间,避免模型数据丢失和精度损失。系统基于改进的有限元逆算法,根据零件形状或带有工艺补充面的工件形状即可快速计算出冲压件的毛坯形状,预测零件的应力应变分布。作为DFM的一个有效载体,系统可应用于汽车覆盖件产品设计初期,帮助企业提高新产品工艺质量和产品质量,缩短新产品开发时间,节省产品开发成本。论文对汽车覆盖件产品设计可成形性同步仿真系统的开发工具CAA以及改进的有限元逆算法的开发思想进行了分析概述。在汽车覆盖件结构特点和成形工艺分析的基础上对系统进行了详细的需求分析和框架、界面设计,并初步确定了系统的工作流程,概况描述了CATIA_BEW系统的总体设计和实现。论文对CATIA_BEW系统的主要关键技术进行了详细介绍。针对系统操作过程中涉及大量数据的创建和修改,系统利用CAA提供的属性操作接口进行了有效的处理;CATIA_BEW系统集成了FASTAMP网格剖分器,相比CATIA自身携带的剖分器,不仅剖分速度快,而且减少了畸形单元;此外利用CATIA的“发布”关联技术实现了系统的同步更新,避免了因初始模型的修改导致繁琐的有限元模拟操作。论文通过对比汽车底板和汽车外围板的系统模拟结果和实验结果,验证了系统具有良好的稳定性,且误差较小,求解速度快,满足工业的实际要求。更多还原

【Abstract】 Automobile panels with complicated structure and big overall dimensions always contain complex local flanging shape and demand high forming quality. In the product design phase, traditional methods are based on experience or simple theories to design product shape, which have high requirements on engineers and technicians. With the advancement of technology and computer technology, finite element simulation technology can help designers in the product design stage to consider various factors which affect the manufacturability of the products, obtain more accurate results in a very short period of time, save a lot of product development costs and shorten product development cycles.The research of this paper is aided by Chinese NC special projects:Stamping Dies of the whole body side panels, fenders and interiors of new environmentally friendly materials in C-Class car (No.2009ZX04013-031) and Chinese National Natural Science Foundation:Complex automotive structural parts multi-position progressive die strip design fast simulation model and the key algorithm (No.50905067). The paper employed CAA secondary development, designed and developed automobile panels’ formability simulation system BEW (Blank Estimation Wizard) based on CATIA platform. By using the publication function of CATIA, the system can update the CAD model and CAM model synchronously to reduce the repeated CAE modeling time in the early product design phase and avoid loss of the data and accuracy. System is based on improved finite element inverse approach, which can calculate the blank shape of stamping parts quickly and predict the stress and strain distribution of the parts according to shape or technologic surface fo the workpiece. As an effective carrier of DFM, the system can be applied to the early design of automobile panel to help enterprises to improve new products’ process quality and product quality, shorten product development time and save product development costs.The paper outlined and analyzed the development tools CAA and the development idea of finite element inverse approach of automobile panels’ formability simulation system. On the basis of analying the automobile panels’ structural features and forming process, the paper made a detailed needs analysis and designed the framework and interface of the system, setted the work flow initially, profiling the CATIA_BEW overall system design and implementation.The paper introduced the key technology of the CATIA_BEW system in detail. The system created and modified large amounts of data during the system operation process by employing the property operation interface of CAA.CATIA_BEW system integrates FASTAMP mesh subdivision device, which is quicker and reduce malformed units compared to CATIA’s own subdivision device. What’s more, the models can be updated synchronously by using CATIA’s "publication" technology to avoid the complicated operations of the finite element model for the modification of the initial model.The paper verified the system’s stability by comparing the simulation and experimental results of car floor and outside board. The error is small and solving speed is fast, which can meet the practical requirements of industry.更多还原