中文摘要：

This paper presents a new description for brittle solids with micro-cracks under plane strain assumption.The basic idea is to extend the conservationlaws such as the J_j-vector and M-integral analysis used in single crack problems tostrongly interacting crack problems.The M-integral contains two distinct parts.Oneof them is a summation from the well-known relation between the M-integral and thestress intensity factors(SIF)at both tips of each crack.The other,called as theadditional contribution,is obtained from the two components of the J_j-vector andthe coordinates of each microcrack center in a global system.Of great significanceis the clarification of the confusion about the dependence of the M-integral on theorigin selection of global coordinates,provided that the vector vanishes at infinityand that the closed contour chosen to calculate the integral and the vector enclosesall the microcracks completely.The M-integral is equivalent to the decrease of thetotal potential energy of the microcracking solids with the strong interaction beingtaken into account.The M-integral analysis,from a physical point of view,doesplay an important role in evaluating the damage level of brittle solids with stronglyinteracting microcracks.