锻压技术

应变路径变化对材料韧性断裂的影响

英文标题：Influence of strain path change on material ductile fracture

作者：朱险锋王婷婷庄新村赵震

单位：上海交通大学

分类号：TG113.2

出版年,卷(期):页码：2016,41(6):122-127

摘要：

为研究非比例加载条件下应变路径的变化对材料韧性所产生的影响，设计了一组包含宽应力三轴度的非比例加载试验，得到相应的载荷-位移/扭角曲线。运用ABAQUS/Explicit及用户子程序VUSDFLD，基于试验与模拟相结合的方法确定断裂起始点，研究复杂加载条件下断裂起始点的平均应力三轴度、罗德系数和等效断裂应变的变化趋势，分析应变路径变化对断裂成形极限的影响。结果表明：预加载的存在加快了断裂进程，且随着预加载程度的增加，材料的韧性断裂出现的愈早。对于拉-扭试验，在预扭阶段应变沿着纯扭趋势发展，而进入拉伸阶段后应变并非沿着单拉的应变路径进行变化；对于压-扭试验，在预压阶段应变沿着单向压缩的应变路径变化，而扭转阶段则沿着平行于纯扭的应变路径变化。

In order to investigate the influence of strain path change on material ductile fracture under non-proportional loading, a series of wide stress triaxialities tests were implemented to acquire the load-stroke/torsional angle curves. Then, the fracture origin was determined by software ABAQUS/Explicit and VUSDFLD subroutine based on combining the experiment with and numerical simulations. Furthermore, the evolutions of average stress triaxiality, average lode angle parameter and equivalent fracture strain of fracture origin were studied under the complex loading, and influence of strain path change on fracture forming limit was analyzed. The result shows that the pre-loading promotes the fracture process, and fracture toughness of material appears earlier than before with the increase of pre-loading. For tension-torsion tests, the strain firstly develops along the pure torsion path at the pre-torsion stage, and then it is not along the strain path of uni-tension at the tension stage. For compression-tension tests, the strain firstly develops along the strain path of compression at the pre-compression stage, and then it is parallel to the strain path of torsion at the torsion stage.

基金项目：

基金项目:国家自然科学基金资助项目（51575345）

作者简介：朱险锋（1990-），男，硕士研究生 E-mail：xianfengzhu@sjtu.edu.cn 通讯作者：庄新村（1980-），男，博士，副研究员 E-mail：georgezxc@sjtu.edu.cn

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