大理岩破坏过程的三维细观弹塑性损伤模拟研究

3D numerical simulation of elasto-plastic damage and failure process of marble rock

为了考虑岩石细观局部塑性变形,基于应变空间理论导出细观弹塑性损伤模型,采用有限元计算方法实现岩石三维破裂过程的数值模拟。提出细观破坏单元网格消去法,利用位移加载来实现岩石逐渐破裂过程;模拟二维、三维大理岩三点弯曲梁弹塑性损伤破坏试验,得到岩石非线性应力–应变曲线和不同载荷阶段弹塑性损伤破裂演化系列图像;分析细观非均匀性对岩石宏观破裂力学行为的影响。试验研究表明,三维破裂比二维破裂更为复杂,本文所建模型可以有效地模拟岩体的三维破坏过程。

In order to consider local plastic deformation of rocks on mesoscopic level, a constitutive model of elasto-plastic damage based on the incremental theory was deduced in strain space, and the failure elements deleting method was used to simulate crack propagation in program so as to explicitly show the extension of the cracks in rocks. By following a simple elasto-brittle constitutive relation, the complete progressive failure of 3D rock was obtained. Finally, three-point bending beam experiments were conducted. Complete nonlinear stress-strain curves as well as facture images during the damage evolution process were obtained. It was by the numerical simulation results shown that 3D failure process was much more complicated than 2D failure process. The proposed model was a useful and effective tool to simulate the failure process of heterogeneous materials.