干摩擦下含不同角度预制裂纹丁腈橡胶的裂纹扩展

Crack Growth of Nitrile Rubber with Different Precracked Angle Under Dry Friction

干摩擦下橡胶裂纹的扩展方向与初始预制裂纹角度息息相关。目前人们对于橡胶裂纹扩展研究主要集中在橡胶材料配方对裂纹扩展的影响以及在拉压或剪切作用下裂纹的扩展规律等方面,很少有人研究干摩擦下初始预制裂纹角度对裂纹扩展的影响。文中通过往复式摩擦试验和ANSYS有限元分析,观察不同预制裂纹角度橡胶试样的裂纹扩展过程,并计算裂纹尖端撕裂能大小。结果表明,裂纹扩展过程中扩展路径基本上可分为初始扩展阶段、水平扩展阶段和最后断裂阶段;随着裂纹角度的增加,裂纹扩展三个阶段所需的时间都有所延长;裂纹尖端的撕裂能随初始预制裂纹角度的增加而逐渐增大,有限元分析结果很好地证实了试验结果。

Propagation direction of rubber crack under dry friction is closely related to the initial precracked angle.The study on crack propagation of rubber was now mainly concentrated on the effect of rubber formula and crack propagation mechanism under the action of tension,compression or shear,while there was few research about the effect of precracked angle on the crack propagation under dry friction condition. In this paper,crack propagation direction of rubber specimens with different precracked angles was observed and the tearing energy of crack tip was calculated through the reciprocating friction experiment and ANSYS finite element analysis. The results show that the crack propagation path of rubber can be basically divided into the initial propagation stage,horizontal propagation stage and final fracture stage.With the increase of procracked angle,the time for the above three stages is increased. The tearing energy of crack tip is increased with initial precracked angle,and the results of finite element analysis are in good agreement with that of experiment.