预制裂纹角度对橡胶拉伸断裂影响的有限元分析

初始裂纹的形态影响着裂纹尖端的应力场和扩展方向,进而决定着橡胶材料的使用寿命。目前人们关于预制裂纹试样拉伸断裂的研究主要集中在直裂纹,很少涉及预制裂纹角度的改变对橡胶拉伸断裂的影响。文中应用ANSYS有限元分析软件计算拉伸状态下含不同裂纹角度橡胶试样裂纹尖端的等效应力值和撕裂能的大小,判断裂纹是否扩展及扩展方向,并对橡胶试样进行拉伸验证试验测试。结果表明,在拉伸断裂过程中,裂纹尖端的应力值和撕裂能随着初始预制裂纹角度的增大而增大,裂纹尖端形状均由初始的尖点变成圆弧状;含不同裂纹角度橡胶试样的拉伸断裂形貌与裂纹预测扩展方向基本一致,验证了有限元分析的正确性。

Finite Element Analysis for the Influence of Precracked Angle on the Tensile Fracture of Rubber

The shape of initial crack affects the stress field and the expansion direction of the crack tip,which decides the service life of the rubber material.At present,the research on the tensile fracture of precracked sample is mainly focused on the straight crack,and the influence of precracked angle on the tensile fracture of rubber is seldom studied.Equivalent stress and tear energy of crack tip was calculated and whether the crack should be expanded and the expansion direction was determined using ANSYS finite element software for rubber samples with different precracked angles under tension state.The results show that in the tensile fracture process,the stress and tear energy of crack tip increase with increase of the initial precracked angle,and the shape of crack tip is varied from the initial cusp to arc.The tensile fracture morphology of rubber specimen is basically the same as the prediction propagation direction,which verifies the correctness of the finite element analysis.