韧性断裂准则及损伤模型在冲裁有限元模拟中的应用研究

发布时间：2018-05-06 09:25

本文选题：有限元模拟 + 冲裁　；参考：《锻压技术》2015年06期

【摘要】：在冲裁有限元模拟中,韧性断裂准则的选择会对冲裁件断面质量与尺寸精度产生很大影响。为了获得符合实际的模拟结果,进而优化冲裁工艺,重点研究了一些常用的韧性断裂判定依据,并从物理学角度阐述了韧性断裂机制。基于试验的韧性断裂准则,考虑了变形历史中的应力应变关系,使用由反求法确定的临界值来判定韧性断裂的发生与否。基于连续损伤力学建立的损伤模型,考虑了变形过程中损伤累积对材料本构关系的影响,能够更准确地描述断裂过程。此外,还分析了冲裁有限元模拟中的关键技术,如采用任意拉格朗日欧拉方法来解决网格畸变问题,使用单元分裂、单元分离与单元删除等技术来处理裂纹的萌发与扩展。探讨了目前韧性断裂模拟中存在问题以及未来发展方向。
[Abstract]:In the finite element simulation of blanking, the selection of ductile fracture criterion will have a great influence on the quality and dimensional accuracy of the section. In order to obtain practical simulation results and optimize blanking process, some commonly used basis for judging ductile fracture are studied emphatically, and the mechanism of ductile fracture is expounded from the point of view of physics. Based on the experimental ductile fracture criterion, the stress-strain relationship in the deformation history is considered, and the critical value determined by the inverse method is used to determine whether the ductile fracture occurs or not. Based on the damage model established by continuous damage mechanics, the effect of damage accumulation on the constitutive relationship of materials during deformation is considered, and the fracture process can be described more accurately. In addition, the key techniques in the finite element simulation of blanking are analyzed, such as the use of arbitrary Lagrangian Euler method to solve the mesh distortion problem, the use of element splitting, element separation and element deletion to deal with the crack germination and propagation. The present problems in ductile fracture simulation and its future development are discussed.
【作者单位】：北京科技大学材料科学与工程学院;
【分类号】：TG386

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