Fundamentals of process design for dimensionally accurate roll forming of asymmetrical profile geometries

非对称型材几何形状的尺寸精确滚压成型的工艺设计基础

• 批准号: 407937637
• 负责人: Professor Dr.-Ing. Peter Groche
• 金额: --
• 依托单位: Institut für Produktionstechnik und Umformmaschinen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407937637?language=en
• 关键词: Fundamentals; process; design; dimensionally; accurate

Roll forming is a continuous manufacturing process for cold rolled profiles, which sees use besides others in the automotive and furniture industry. In contrast to discontinuous bending methods, like die bending, the sheet metal is formed in a three-dimensional forming process. Besides the bending of the cross section additional process-related deformations happen which lead to profile defects. Especially asymmetrical profiles are always subjected to torsion and multi-dimensional bowing.Nowadays, the use of Finite-Element-Simulations during the process design is the only way to detect the profile defects. Due to the time intensive calculations the application of FEM-simulations is limited. Furthermore, the interactions between process parameters and profile defects are not fully understood, so the process design is mainly empirical and the resulting profile defects have to be compensated in time-consuming correction processes.The project aims at the prediction, analysis and reduction of the defects after roll forming of an asymmetrical hat profile. The asymmetrical hat profile is suited best, because it can represent complex profile geometries with several bending zones. Within the project the process design will be improved in two ways. On the one side, an analytical model for the prediction of torsion of asymmetrical hat profiles, without the necessity of FEM-simulations, is developed to be used as the initial value for the numerical optimization. On the other side, numerical and experimental investigations of roll forming of asymmetrical hat profiles are conducted to characterize and analyse the process-related additional deformations, the resulting profile defects as well as the influence of process parameters of the roll forming process. Based on the results, effective counter measures can be deduced and numerically investigated. Following the investigation, the counter measure found most effective, is optimized by an optimization algorithm coupled with the FEM-simulations. Thereby, the parameters of the counter measures are optimized with regard to a balanced state of strains within the profile. Finally, the counter measure and the optimization algorithm are validated experimentally.By deepening the understanding of the creation of profile defects of complex profile geometries, the developing of effective counter measures and the development of an analytical model to predict torsion in the early design stage, this project contributes to an more accurate and efficient process design with the aim to significantly shorten correction processes and to increase the production rate.

辊轧成型是一种连续生产冷轧型材的工艺，在汽车和家具行业中也有应用。与不连续弯曲方法（如模具弯曲）相比，金属板在三维成形过程中成形。除了横截面的弯曲之外，还会发生与工艺相关的额外变形，从而导致轮廓缺陷。特别是非对称型材往往会受到扭转和多维弯曲的影响，目前，在工艺设计中使用有限元模拟是检测型材缺陷的唯一方法。由于时间密集型计算的应用有限的有限元模拟。此外，由于工艺参数与板形缺陷之间的相互作用还没有完全了解，因此工艺设计主要是经验性的，由此产生的板形缺陷必须在耗时的校正过程中进行补偿。本项目旨在预测、分析和减少非对称帽形板形辊轧成形后的缺陷。不对称帽形轮廓最适合，因为它可以表示具有多个弯曲区域的复杂轮廓几何形状。在该项目内，将从两个方面改进工艺设计。一方面，不需要有限元模拟的非对称帽形型材的扭转预测的分析模型被开发用于作为数值优化的初始值。另一方面，对非对称帽形型材的辊轧成形进行了数值和实验研究，以表征和分析与工艺相关的附加变形、由此产生的轮廓缺陷以及辊轧成形工艺的工艺参数的影响。根据计算结果，可以推导出有效的对抗措施，并进行数值研究。在调查之后，发现最有效的对策是通过与FEM模拟相结合的优化算法来优化的。由此，针对分布内的应变的平衡状态来优化对抗措施的参数。最后，通过实验验证了对策和优化算法。通过加深对复杂轮廓几何形状的轮廓缺陷产生的理解，开发有效的对策和开发在早期设计阶段预测扭转的分析模型，该项目有助于更准确和有效的工艺设计，目的是大大缩短校正过程，生产率。