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上海交通大学硕士学位论文汽车覆盖件翻边成形切边线优化设计及算法研究姓名:白燕超申请学位级别:硕士专业:材料加工工程指导教师:阮雪榆;陈劼实20100201上海交通大学工学硕士学位论文 摘 要 I 汽车覆盖件翻边成形切边线优化设计及算法研究 汽车覆盖件翻边成形切边线优化设计及算法研究 摘摘 要要 汽车覆盖件主要指覆盖汽车发动机和底盘、构成驾驶室和车身的一些零件,如挡泥板、顶盖、车门外板、发动机盖、水箱盖、行李箱盖等。和一般冲压件相比,汽车覆盖件具有材料薄、形状复杂、多为空间曲面且曲面间有较高的连接要求、结构尺寸较大、表面质量要求高、刚性好等特点。所以覆盖件在冲压工艺制定、冲模设计和模具制造上难度都较大,并具有其独特性。 汽车覆盖件冲压成形工艺相对一般零件的冲压工艺更复杂,所需要考虑的问题也更多,汽车覆盖件的冲压工序一般要 46 道工序,多的有近 10道工序。要获得一个合格的覆盖件,通常要经过下料、拉深、切边(或有冲孔) 、翻边(或有冲孔) 、冲孔等工序才能完成。而拉深、切边和翻边是最基本的三道工序。在汽车覆盖件翻边成形中,影响翻边成形性和成形精度的一个重要因素就是零件切边线设计是否合理,所以翻边成形的关键是如何快速准确的确定出拉延后的切边线。 当前生产中,还没有一个快速有效的确定切边线的方法,确定切边线的方法大多采用的是试错法,为得到所需翻边高度和形状要反复修正切边模轮廓,不仅造成大量材料与人工浪费,也影响整个制模与试模周期,增大制模成本,影响新产品的开发进度。 上海交通大学工学硕士学位论文 摘 要 II 如何确定切边线的尺寸和形状,使翻边后突缘轮廓正好达到零件所需翻边高度,对于缩短模具制造周期,减少生产成本都具有重要意义,同时也是整个模具行业亟待解决的一大难题。 本文基于 Microsoft.net 技术开发一款优化设计复杂翻边切边线的程序,研究方法是采用数值的方法来预示优化修边线,把有限元仿真技术应用于传统的逐次逼近法中,把过去的手工试验修改坯料外形发展为通过有限元软件反复模拟修改坯料外形。 提出了一种基于误差修正的预示复杂翻边切边线的迭代算法,在LS-DYNA 有限元仿真的基础上, 根据仿真结果轮廓与目标轮廓的形状误差来不断修正毛坯形状,一至两次的迭代修正后即可得到精确的切边线形状。在程序中实现了 LS-DYNA 求解器的自动调用, 大大提高了切边线的优化效率。最后通过三个翻边件的算例验证及物理实验证明了该方法的有效性。 关键词:关键词:翻边,切边线,优化,误差修正,迭代算法,LS-DYNA 上海交通大学工学硕士学位论文 ABSTRACT III OPTIMUM DESIGN AND ALGORITHM STUDY OF AUTO BODY PARTS FLANGING TRIMMING LINE ABSTRACT Auto body parts mainly include covers of the engine and chassis, parts of cab and body, such as mudguard, roof, car door panel, engine cover, radiator cover and trunk cover. Comparing with general stamping parts, there are some especial characters of auto body parts, such as little thickness, complex shape, complex surface, higher connecting requirements between surfaces, large structure size, high surface quality requirements and rigidity. So, its difficult for auto body parts in designing stamping process, designing and manufacturing die. Comparing with general stamping parts, the stamping process of auto body parts is more complex. There are more problems that need to be considered. The stamping processes of auto body parts generally include 4 to 6 work procedures, and whats the most include nearly 10 work procedures. A qualified auto body part is usually completed through blanking, drawing, cutting edge (or punching), flanging (or punching), punching and other processes. The deep drawing, trimming and flanging is the most basic three processes. For flanging of auto body part, the most important factor that impact flanging formability and forming accuracy is the rationality of cutting edges. So the key of flanging forming is how to quickly and accurately prefigure the trimming line after deep drawing. 上海交通大学工学硕士学位论文 ABSTRACT IV In the production of auto body parts, there is not yet a quick and effective method to prefigure the trimming line. However trial and error method is used mostly. In order to obtain the required height and shape of flanging, we have to repeatedly correct the size and shape of trimming die, which not only results in great waste of materials and manpower, but also adds the entire time of manufacturing and testing die, increasing the cost of manufacturing tools and holding up the development progress of new product. How to prefigure the size and shape of the trimming line, so that there is a perfect flange after the flanging process, is very important for reducing die manufacturing cycle and the product cost. But for the entire die industry, it is also a major problem needed to be solved. Based on Microsoft.net, a process of predicting optimal trimming line of complex flanging was developed. The researching method was numerical methods. The finite element simulation method was used into the traditional successive approximation method. The method of modifying blank shape by hand in the past was replaced by the finite element software. An iterative algorithm that prefigures complex flanging trimming line based on error correction was proposed. Based on the finite element simulation of LS-DYNA, according to the error values of simulation results and the target curve, the blank is corrected. After one or two iterations, an exact trimming line would be obtained. The program could automatically call LS-DYNA solver, which greatly increased the efficiency of the trimming line optimization. A flanging simulation study proved that the method was effective. KEY WORDS: flanging, trimming line, optimum, error-correction, iterative algorithm, LS-DYNA 上海交通大学上海交通大学 学位论文原创性声明学位论文原创性声明 本人郑重声明:所呈交的学位论文,是本人在导师的指导下,独立进行研究工作所取得的成果。除文中已经注明引用的内容外,本论文不包含任何其他个人或集体已经发表或撰写过的作品成果。对本文的研究做出重要贡献的个人和集体,均已在文中以明确方式标明。本人完全意识到本声明的法律结果由本人承担。 学位论文作者签名: 日期: 年 月 日 上海交通大学上海交通大学 学位论文版权使用授权书学位论文版权使用授权书 本学位论文作者完全了解学校有关保留、使用学位论文的规定,同意学校保留并向国家有关部门或机构送交论文的复印件和电子版,允许论文被查阅和借阅。本人授权上海交通大学可以将本学位论文的全部或部分内容编入有关数据库进行检索,可以采用影印、缩印或扫描等复制手段保存和汇编本学位论文。 保密保密,在 年解密后适用本授权书。 本学位论文属于 不保密 不保密。 (请在以上方框内打“
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