中文摘要：

基于扩展有限元法,建立了压应力状态下多裂纹扩展过程数值模拟方法。该方法采用罚函数法考虑裂纹面的摩擦,然后对刚度矩阵和荷载列阵进行修正,通过迭代计算可以得到压应力状态下裂纹的扩展路径及应力场。单元形函数中包含有间断函数和裂尖富集化函数,因此裂纹的扩展路径与网格无关,从而避免了裂纹扩展计算过程中不断对网格重新划分。由于考虑了裂纹闭合的影响,此数值模拟方法适用于岩土工程中常见的压剪应力状态多裂纹扩展。最后,将此数值模拟结果与相似模型试验结果进行对比,分析表明与相似模型试验结果接近,验证了此数值模拟方法的可行性。

英文摘要：

A numerical simulation method for modeling the growth of multiple frictional cracks in linear elastic media within the framework of the extended finite element method is presented.The contact constraint on crack surface is embedded within the total stiffness matrix by the penalty method,in which the load vectors are modified too.The path of crack growth and stress field are determined through iterative computations.Because additional discontinuous functions and enriched tip elements are added in the displacement field,the geometry of cracks is independent of the finite element mesh.As a result,remeshing is not necessary to model crack propagation.Because the frictional contact of crack surface is taken into account,the present method is fit for modeling the growth of multiple cracks in geomaterials under compressive loads.Finally,the method is employed to simulate multiple crack-growth when frictional contact exists on the crack surfaces,and the results show good agreement with the experimental ones.