基于二元介质模型的岩土类材料破损过程数值模拟

Simulation of breakage process of geomaterials by binary-medium model

岩土类材料是非均质的具有微缺陷的天然材料,岩土破损力学将岩土材料抽象成由胶结元和摩擦元组成的二元结构体。本文在细观尺度上把胶结元看成理想弹脆性材料,把摩擦元看成硬化型弹塑性材料,计算时通过受荷过程中胶结元破损并逐渐向摩擦元的转化来模拟岩土材料的破损过程。最后进行平面应变受压应力状态下的数值计算,探讨不同侧向应力状态下岩土类材料的破损发展过程和相应的位移状态。结果表明,本文建议的模拟方法可以较好的模拟岩土类材料的破损过程和力学响应。

Geological materials are inhomogeneous and having micro cracks and micro voids. Under the theoretical framework of breakage mechanics for geological material, the geomaterials are conceptualized as binary medium consisting of bonding elements and frictional elements, which are idealized as elasticbrittle element and hardened elastic-plastic element respectively in meso-seope. The fracture process of geomaterial is simulated by the transformation of fracturing or breaking of bonding element into frictional element in the process of loading. Finally, the numerical simulations of compression under plane strain conditions with different confining pressures are carried out. The numerical examples show that the mesoscope FEM based on the binary-medium model can satisfactorily simulate the breakage process and deformation properties of geomaterials.