Abstract: In order to clarify the crack change processes after the liquid penetrated into the cracks， the two-dimensional liquid-filled model of a rolling contact disk with a crack was established. The cavity was composed of the crack surface and the contact surface of the disk surface. The movement of the disc deformed the crack surface， and the pressure in the cavity increased as the liquid was compressed. In addition， the cavity pressure applied to the crack surface accelerated the crack propagation. Based on the changes of the crack surface contact states， the stress intensity factor curve and the crack propagation direction of the cracks under the conditions of cavity formation， cavity sealing and liquid leakage were analyzed. The results show that the pressure in the cavity is less than the maximum pressure at the crack contact positions. Under the action of liquid pressurization， the crack propagation mode changes from Ⅱ to Ⅰ. As the length and width of the crack increase， the crack propagation mode changes from Ⅱ to Ⅰ. As the crack geometry increases， the liquid pressurization effect is significantly enhanced. As the crack growth， self-sealing and leakage of the dynamical cavity occur in the processes of liquid leakage. 

Key words: fluid pressurization, crack growth, stress intensity factor, cavity entrapment, self-sealed

摘要： 为研究液体渗入裂纹后裂纹的演变过程，建立了滚动接触圆盘-平面裂纹充液二维模型。裂纹表面与圆盘-平面接触面组成腔体结构，圆盘的运动使裂纹表面发生变形、腔体体积减小从而导致腔体内压力增大，最终表面裂纹在腔体高压作用下加速扩展。基于表面裂纹接触状态的变化，研究腔体形成、密封和泄漏三个阶段裂纹应力强度因子曲线及扩展方向的演变。结果表明，腔体内部压力小于裂口接触位置最大压力，液体增压效应随裂纹几何尺寸的增加显著增强，增加裂纹长度与裂口宽度使裂纹扩展模式从Ⅱ型转为Ⅰ型；随着裂纹扩展，腔体内部的液体泄漏使腔体产生动态自密封-泄漏现象。

关键词: 液体增压, 裂纹扩展, 应力强度因子, 腔体密封, 自密封