论文部分内容阅读
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 GTN model with shear correction under non-proportional loading conditions, based on the experimental results of tensile shear path loading of a group of notched round bar specimens, finite element software ABAQUS / Explicit module and user subroutine VUMAT parallel simulation analysis. The results show that under the pre-deformation condition, under the preloading condition, the increasing pre-strain will increase the growth rate of the hole during the subsequent drawing process, resulting in the early fracture of the material. At the same time, the damage evolution mechanism of non-proportional loading process was studied combining the macro and micro-morphology analysis. The fracture mechanism of AA2024 aluminum alloy under tensile shear loading is tensile-shear mixed fracture. With the increase of pre-twisting, shear fracture gradually replaced tensile fracture as the dominant fracture mode.