New methodology of springback compensation for Advanced High Strength Steels based on geometrical modifications

基于几何修改的先进高强度钢回弹补偿新方法

基本信息

批准号：
267134330
负责人：
Professor Dr.-Ing. Mathias Liewald
金额：
--
依托单位：
Institut für Umformtechnik (IFU)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/267134330?language=en
关键词：
New methodology springback compensation Advanced

项目摘要

Nowadays, the automotive industry is challenged by increasing environmental regulations as well as continuously enhancement of the standard requirements regarding to passengers safety. Such tendencies lead to increased use of advanced high strength steels (AHSS) for manufacturing of car body components which are placed in many areas within car body structure. However, the potential application of high strength steels is still limited since many issues have to be investigated related to formability and springback.There are various strategies to minimize springback by means of process parameter variation during the press stroke or by use of additional retention forces by the blank holder. These strategies were already applied successfully in the forming of high-strength steel alloys up to 600 MPa tensile strength, and have proven successfully in practice. When using these techniques for forming of more stronger steel materials (tensile strength higher than 600 MPa), results achieved and knowledge applied with respect to component accuracy are not satisfactory due to the increased tendency towards springback and twisting. For cold forming of such steel grades until now a defined and valid strategy or method that can be used for springback and twisting compensation is missing.The motivation of the research work basically stands for lack of such methodology to reduce springback and torsion observed in load carrying components of passenger cars, as well as to find a sophisticating compensation strategy for manufacturing such steel grades. The methodology for springback compensation will be dependent on local stress-strain state as well as on magnitude of sidewall curl and torsion moment of the component. The method to be developed first will be based on optimization of binder shapes, on global and/or local application of hardening functions, on special indentations in identified areas of component as well as on details in shape for counter striking objectives of component radii.

如今，通过增加环境法规以及对乘客安全的标准要求的不断提高，汽车行业受到挑战。这种趋势导致高级高强度钢（AHSS）的使用增加用于制造汽车车身组件，这些车身组件位于汽车体结构内的许多区域。但是，高强度钢的潜在应用仍然受到限制，因为必须研究许多与表现性和弹回有关的问题。有各种策略通过新闻冲程期间的过程参数变化或通过空白持有人使用额外的保留力来最大程度地减少回弹。这些策略已经成功地应用于高强度的钢合金高达600 MPa抗拉力强度，并在实践中成功地证明了这些合金。当使用这些技术形成更强大的钢材材料（高于600 MPa）时，由于增加了弹回和扭曲的趋势，因此获得的结果和有关组件准确性的知识并不令人满意。直到现在为了冷的形成此类钢等级，可能缺少一种可用于回弹和扭曲补偿的定义且有效的策略或方法。研究工作的动机基本上代表缺乏这种方法来减少在乘用车的负载载荷组件中观察到的浮回和扭转，并找到用于制造此类钢铁级的复杂补偿策略。回弹补偿的方法将取决于局部应力 - 应变状态以及组件的侧壁卷曲和扭转力矩的大小。首先要开发的方法将基于粘合剂形状的优化，用于硬化功能的全局和/或局部应用，对组件的特殊凹痕以及组件的详细信息的特殊凹痕，以实现组件radii的反击目标。