纯铝试样厚度与缺口深度对拉伸破坏的影响

Effect of specimen geometry on tensile fracture of notch specimen of pure aluminum

对含缺口矩形截面纯铝试样进行拉伸破坏试验,通过改变试样厚度和缺口深度研究应力三维度对试样破坏的影响;采用有限元方法对试样的拉伸破坏进行了模拟分析。试验和模拟分析表明:断裂应变随试样厚度的增大而增大,而缺口深度增大时断裂应变却减小,因此,以往应力三维度增高导致断裂应变下降的观点不一定正确。

Tensile fracture tests are carried out using notched specimen of pure aluminum with rectangle section. The effect of the thickness of notched specimen with different depth on the failure is analyzed,in which the stress triaxiality in specimen under tension is designed through changing the specimen＇ s geometry. The FEM numerical simulation is further performed to analyze the deformation and damage process of the specimen under tensile. According to the experiments and numerical simulations, the results indicate that the thicker the specimen the larger the fracture strain will reach and the deeper the notch the smaller the fracture strain will be. This result means the opinion considering that the higher stress triaxiality will cause fracture strain decrease may not be always true.