无厚度三节点节理单元在裂纹扩展模拟中的应用  

APPLICATION OF NON-THICKNESS THREE-NODE JOINT ELEMENT TO CRACK PROPAGATION SIMULATION

作　　者：戚靖骅[1] 张振南[1] 葛修润[1] 邱一平[1] 

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《岩石力学与工程学报》2010年第9期1799-1806,共8页Chinese Journal of Rock Mechanics and Engineering

摘　　要：节理厚度在实际工程中很难用常量描述,为便于描述节理的力学行为,在原三节点节理单元的基础上构造无厚度三节点节理单元,并推导出相应的刚度矩阵。由于三节点节理单元与原三角形单元共享节点,因而它在模拟裂纹扩展过程中无需对网格进行重新划分;另外,在网格剖分时,也无需考虑裂纹体的几何完整性,可直接对结构进行三角网格剖分。因此,该方法可为裂纹的模拟提供极大的便利,并显著提高计算效率。相应的大理石模拟试验表明,该方法在岩石裂纹扩展的模拟中是有效可行的。It is difficult to describe the thickness of joint with a constant in practical engineering.In order to model the mechanical behaviors of joints conveniently,a non-thickness three-node joint element is proposed on the basis of the existed three-node joint element;and the stiffness matrix of non-thickness three-node element is deduced.For it shares the same nodes with original three-node triangle element,the non-thickness three-node joint element is adopted to model crack propagation without remeshing or adjustment of the original mesh.Another advantage is that the cracked body is meshed without considering its geometry integrity and the existence of joints or pre-existed crack in the procedure of mesh generation;and then the triangular element intersected by crack or joint is automatically transformed into the three-node joint element to represent pre-existed cracks.These make the numerical simulation of crack propagation highly convenient and efficient.After the maximum strain failure criterion is chosen to determine whether the element is intersected by the extended crack or not,the extended crack is located in the model based on hypothesis of the direction of crack propagation perpendicular to the direction of the extended crack passing through the centroid of the triangle element.By simulating the marble plates with double parallel cracks subjected to uniaxial compressive loads,it is shown that the simulated results are in good agreement with the experimental results,so as to show that the present method is valid and feasible in rock crack propagation simulation.

关 键 词：岩石力学 三节点节理单元 裂纹 节理 数值模拟 

分 类 号：TU45[建筑科学—岩土工程]