基于格构模型的岩石类材料破坏过程的数值模拟

Lattice model for simulating failure process of rock

本文采用二维格构模型在细观尺度上模拟岩石类材料的破坏过程 .格构模型将连续介质离散为由弹性杆或梁单元组成的二维格构网格 ,单元采用简单的本构关系和破坏准则 ,单元之间的参数可互有差异 ,以引入材料的非均质性 .在外载作用下对整体网格进行线弹性分析 ,计算出格构中各单元的局部应力 ,超过断裂阈值的单元将破坏 ,材料的破坏过程通过单元的依次破坏来模拟 .本文使用格构模型分析了单轴拉伸破坏和单边切口梁的剪切破坏 .数值模拟结果表明 ,格构模型可作为岩石、混凝土类材料破坏分析的一种有效方法 .

A lattice model is developed to simulate the failure process of heterogeneous brittle materials.It is assumed that a continuum can be represented at the meso-level by a connected lattice of elastic-brittle truss of beam elements.The heterogeneity of the material can be implemented following different manners.The process of fracture is simulated by performing a linear elastic analysis of the lattice under loading and removing an element from the lattice that exceeds a certain failure threshold.After removal of an element the analysis is repeated.With this model,uniaxial tension and four-point-shear experiments of single-edge notched beams are simulated.It is shown that the simulated crack patterns appear quite realistic.