用平板拉伸、缺口拉伸、剪切试验结合断口形貌观察及有限元模拟等方法,对6063铝合金在三种不同应力状态下的变形及损伤行为进行了研究.结果表明:在不同应力状态下该合金的变形及损伤行为存在明显的差异,剪切时材料的断裂应变远大于平板和缺口拉伸时的,而缺口拉伸时材料的屈服强度及峰值应力大于平板拉伸时的;平板拉伸时试样为拉剪混合型断裂,断口由一定比例的韧窝和剪切平面组成;缺口拉伸时试样有明显的颈缩,断口以韧窝为主;剪切断口以剪切平面为主;损伤行为的有限元模拟结果与试验结果吻合较好.

Tensile tests with plat specimen,notched specimen and shear specimen were performed.The fracture appearance was observed by SEM.ABAQUS finite element calculation and simulation were done.The deformation and damage process of 6061 aluminum alloy under three different stress states were analyzed carefully.Studies indicated that there were evident differences in deformation and damage under different stress states.The fracture strain under sheaing state was higher than that of notched tension,while the yield strength and peak stress of the notched tension were higher than those of the plat tension.The plat tension fracture was a mixture model of tension and shearing,composed by a certain proportion of dimples and shear planes.The notched tension facture had evident neck,composed mainly of dimples.The shearing fracture mainly composed of shear planes.The process of deformation and damage of the material under different stress states had been calculated and simulated by finite element software of ABAQUS.The results were consistent with the test results well.