Abstract: Periodic－arrayed indentation is one of the powerful tools in investigating the near surface properties of materials in the micro－/nano－scale．When an elastic substrate in half－plane was subject to indentations by a rigid ，flat － ended punch ，a singular stress field and K－dominant region should arise adjacent to the punch edges．When the intensification of such singular stress fields reaches its critical value， fracture will take place on the surface of the contact boundary． The cracking of indentation was a new type of fracture problem．By using the energy release rate of boundary translation the fracture of indentation has been formulized and critical load and critical cracking angle of the indentation have been found.

Key words: Fracture , Contact mechanics , Stress intensity factors , Indentation

摘要： 周期阵列压痕方法是研究微观摩擦学的工具之一。由于周期阵列刚性压头压在半平面弹性体的表面时，会产生周期的I型奇异压应力场，该奇异应力场的应力集中达到一定程度时，即达到临界条件时，该奇异应力场所在的边界将开裂。压痕边界的开裂问题是一个新型的断裂力学问题，通过边界移动的能量释放率的分析给出了压痕边界开裂能量释放率数学表征，并给出边界开裂的临界载荷和临界开裂角。

关键词: 断裂 , 接触力学 , 应力强度因子 , 压痕开裂