U型工件热力耦合冲压成形数值模拟及实验研究

发布时间：2018-06-13 15:19

本文选题：热成形 + 热力耦合　；参考：《上海应用技术大学》2017年硕士论文

【摘要】：高强度板料冲压成形是一个极其复杂的物理过程,在板料成形时,高强度钢板在冲压过程中比普通钢板更易产生破裂、起皱和回弹等现象。高强度钢板的成形过程是一个高度多元化动态过程。随着钢板强度的提高,其抗变形能力增强,所需的成形力较大,钢板的成形性能较差,容易破裂且回弹大,很难保证零件的精度要求。对于一些复杂的零配件,传统冷冲压工艺得到的工件精度难以保证。由此就引导研究出了热冲压成形技术。热冲压成形技术主要应用于高强度钢板的冲压成形。是一种将板料的成形与淬火同时进行的冲压成形技术。热冲压成形后得到的工件普遍应用于汽车行业,其强度高、满足强度需求的情况下质量轻、耐冲击性能好。相比于冷冲压成形工艺,热成形具有成形性能好、精度高、能生产复杂零配件的优点。为了准确地进行金属板材的热冲压成形过程,避免长时间的试模和修模,降低生产成本,可以采用大型有限元分析软件进行仿真模拟。本研究以热冲压成形中常用的简单工件U型件为研究对象,采用有限元分析软件进行数值模拟,通过与实验分析相结合对U型件的热冲压成形进行深入的研究,建立U型件热力耦合冲压成形有限元模型及冷冲压有限元模型,进而研究改变板料初始成形温度、成形速度和保压时间等对板料成形性能的影响机理,研究模具间隙、板料厚度及材料性能对冷冲压成形回弹影响。提出减小冷成形回弹参考方法,探讨热冲压成形过程中如何协同控制板料初始成形温度、成形速度和保压时间等关键工艺参数的变化,确定优化方案,实现金属板料的控形控性一体化成形,得到符合生产实际需求的工件。
[Abstract]:High strength sheet metal stamping is an extremely complex physical process. During sheet metal forming, high strength steel sheet is more prone to crack, wrinkle and springback than ordinary steel sheet. The forming process of high strength steel plate is a highly diversified dynamic process. With the improvement of the strength of the steel plate, the deformation resistance of the steel plate is enhanced, and the forming force required is large. The forming property of the steel plate is poor, easy to break and the springback is large, so it is difficult to ensure the precision of the parts. For some complicated parts, the precision of the workpiece obtained by traditional cold stamping process is difficult to guarantee. Thus the hot stamping forming technology is developed. Hot stamping technology is mainly used in high-strength steel sheet forming. Is a sheet metal forming and quenching at the same time stamping forming technology. The workpiece obtained by hot stamping is widely used in automobile industry, which has high strength, light quality and good impact resistance. Compared with cold stamping process, hot forming has the advantages of good forming performance, high precision and the ability to produce complex parts. In order to accurately carry out the hot stamping process of metal sheet, avoid long trial and repair of die, and reduce the production cost, a large finite element analysis software can be used for simulation and simulation. In this study, the simple workpiece U-shaped which is commonly used in hot stamping forming is taken as the research object, and the numerical simulation is carried out by using finite element analysis software, and the hot stamping forming of U-shaped workpiece is deeply studied by combining with the experimental analysis. The finite element model of U-shaped thermo-mechanical stamping forming and cold stamping finite element model are established, and the influence mechanism of changing the initial forming temperature, forming speed and holding time of sheet metal on sheet metal forming performance is studied, and the die clearance is studied. The effect of sheet thickness and material properties on springback of cold stamping. This paper presents a method to reduce springback of cold forming, discusses how to control the change of key process parameters such as initial forming temperature, forming speed and holding time of sheet metal in hot stamping process, and determines the optimization scheme. The shape control and controlling forming of metal sheet is realized, and the workpiece that meets the actual production requirement is obtained.
【学位授予单位】：上海应用技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG386

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