【作者】 黄庆宝；

【导师】 陈玉全；

【作者基本信息】 哈尔滨理工大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 随着我国冲压模具高新技术的引进和自身技术的创新,自动化生产水平得到很大的提高,CAD/CAE/CAM集成技术显得空前重要。但我国板料成形CAE技术起步较晚,至今仍未达到市场普及,技术相对落后。板料成形CAE技术是在有限元技术和计算机技术的基础上发展起来的。本文系统全面地分析了国内外有限元模拟技术的特点及适用性,以及我国在板料成形CAE技术发展的现状,重点阐述了动力显式有限元模拟技术DYNAFORM的实用性。由于工业生产中大型汽车覆盖件尺寸大、变形复杂、受力不均等成形难点给加工和成形性的预测带来了诸多困难。本文结合企业提供的典型汽车内板冲压件,应用动力显式有限元模拟技术,针对成形中易产生起皱、破裂等缺陷,提出了具体的解决方法与对策,并给出了板料形状的优化方法,有效地指导了生产。回弹是汽车冲压件中不可避免的现象,为了装配和焊接的需要,必须对其严格控制。针对易产生回弹的典型大弯曲变形汽车结构纵梁件,本文系统分析了回弹产生的原因及控制措施,借助于UG软件,提出了不同的控制回弹的设计方案,结果表明变压边力冲压工艺比恒压边力冲压工艺有较广的适用范围,能更好地控制回弹和板料成形。通过分析大弯曲成形件的成形特点,得出了直接影响成形裕度和回弹量的关键因素是压边力与模具间隙。结合正交试验设计技术与变压边力冲压技术,分析各参数对回弹、成形裕度的影响趋势,并提出了变压边力冲压下优选设计方法,使用优选后的工艺参数可获得较小的回弹,满足了厂家和汽车装配要求。更多还原

【Abstract】 With introducing in more-advanced techniques and innovating self-owned techniques, the level of automatic production in the field of stamping dies has been improved a lot already in our country, and by now the technological collection of CAD/CAM/CAE has become more and more important than anytime before. However, CAE simulating techniques were researched too late to reach a wide range of usage in the market by now with related undeveloped techniques.Sheet forming CAE technique has been developed from the base of FEM and computer techniques. In this thesis, the development, characteristic and the usage range of the both-here-and-broad FEM (Finite Element) simulating technology are introduced systemically in the round, especially the practical characteristic of dynamic explicit FEM simulating technique DYNAFORM.Those large auto panels of large size, complicated deform and unequal stress when stamping do bring forward a good much hardness for manufacturing and forming forecasting. In this thesis, aiming at the typical stamping part supplied by a company, applying dynamic explicit FEM simulating technique DYNAFORM, concrete solutions to wrinkle and break which occur frequently in stamping process have been introduced, and the way to optimize the blank has been given out also, which made a great help to manufacturing.Spring-back is an essential thing in auto stamping parts, however, it should be controlled exactly for requirements of assemble and weld. Aiming at a typical large-bending auto longeron, this thesis systemically analyzed the reason for how spring-back produced and the ways how to control it. Based on CAD software UG NX4.0, different ways to control the spring-back have been brought forward. At the end it showed out that the variable blank holder force had a wider range of usage than the even blank holder force, and also could control the spring-back and blank forming.By analyzing the forming characters of large bending parts, key factors influencing directly the forming degree of redundancy and the spring-back have been obtained, which are blank holder force and the gap between punch and die. Combining the orthogonal trial design and the variable blank holder force process, the influencing tendency to the forming degree of redundancy and the spring-back from gap and other parameters has been analyzed. And at last, an optimized design solution has been promoted under the variable blank holder force process, and by using optimized parameters a small spring back could be obtained. It satisfied the requirement of manufacturers and auto assembling.更多还原