剪切修正GTN模型在拉剪变路径加载问题中的适用性  

Applicability of shear modified GTN model under variable path loading with tension and shearing

作　　者：王婷婷[1] 庄新村[1] 赵震[1] 

机构地区：[1]上海交通大学塑性成形技术与装备研究院模具CAD国家工程研究中心,上海200030

出　　处：《锻压技术》2017年第5期133-140,共8页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51105250)

摘　　要：为评估含剪切修正项GTN模型在非比例加载条件下的适用性,以一组缺口圆棒试样的拉剪变路径加载试验结果为依据,运用有限元软件ABAQUS/Explicit模块及用户子程序VUMAT进行平行仿真分析。研究结果表明:在大预变形下的拉剪变路径加载条件下,增长的预应变会加快后续拉伸过程中孔洞的增长率,导致材料提前断裂。同时,结合断口宏观与微观形貌分析,研究了非比例加载过程材料的损伤演化机理。AA2024铝合金在拉剪变路径加载条件下的断裂机制为拉-剪混合断裂,随着预扭作用的增强,剪切断裂逐渐取代拉伸断裂成为主导的断裂模式。In order to evaluate the applicability of the shear enhanced GTN damage model under non-proportional loading, based on a set of notched round bar tests results under torsion-tension variable path loading, a parallel simulation analysis was carried out by the ABAQUS/Explicit with VUMAT subroutine. The results show that under the condition of tension-torsion variable path loading with large pre-deformation, the growth of pre-strain speeds up the growth rate of voids in the subsequent tension process and results in the material fracture in advance. In addition, combining with the fracture macro and micro morphologies, the damage evolution mechanism under non-proportional loading process was investigated. The fracture mechanism of aluminum alloy AA2024 under the condition of tension-shear variable path loading is a tension-shear mixed fracture, and the shear fracture becomes the dominant fracture mode with the increasing pre-torsion.

关 键 词：非比例加载 GTN模型 应变路径 断裂机理 AA2024铝合金 

分 类 号：TG146.21[一般工业技术—材料科学与工程]