滑动接触效应对裂纹尖端J积分值影响分析

采用断裂力学和有限元法对无润滑摩擦条件下滑动接触效应对摩擦表面裂纹尖端J积分值的影响进行研究,分别得到了不同摩擦因数、接触压力、裂纹长度和裂纹形态下裂纹尖端J积分值的变化规律.结果表明:摩擦效应对裂纹尖端J积分值的影响因裂纹形态不同而变化;对于竖直型裂纹,摩擦效应的增加加剧了裂纹尖端J积分值的变化;对于斜裂纹,在滑动至裂纹附近时,摩擦效应的增加减弱了裂纹尖端J积分值的变化.裂纹尖端J积分值波动幅度随着接触压力的增大而增大.相同接触压力和摩擦效应下,裂纹与滑动速度方向的夹角越小,裂纹尖端J积分值变化越显著.裂纹尖端J积分值随着裂纹深度的增加先增大后减小.

Analysis on Crack Tip J Integral Value Under Sliding Contact Effect

The influence of sliding contact effect on crack tip J integral value was investigated by fracture mechanics and finite element analyses under dry friction. The variation regulation of crack tip J integral value under different friction coefficient， contact pressure， crack length and crack modality was obtained. The results show that the variation of crack tip J integral value is different with crack modality while the friction effect is considered. The increasing of friction effect aggravates variation of the crack tip J integral value for vertical crack. For oblique crack， the increasing of friction effect weakens variation of the crack tip J integral value in the vicinity of sliding to crack. The fluctuation range of crack tip J integral value increases with contact pressure increasing. The smaller the included angle between the direction of the sliding velocity and the crack， the more significantly the crack tip J integral value changes under the same contact pressure and frictional effects. The J integral value first increases and then decreases as the crack deepens.