考虑空间相关尺度特征的细观力学模型及其应用

天然岩石材料内部存在各种缺陷，在微、细观尺度表现出高度的非均质特性。基于连续介质力学框架，采用非线性标量损伤本构关系描述岩石材料的变形与破坏行为，建立了岩石细观损伤本构模型，并在常规Weibull随机分布模型基础上，引入空间相关尺度因子以模拟实际岩石材料各项物理力学指标具有的空间相关特征。选取典型岩石单轴拉伸试验算例，分析随机场内空间相关尺度因子的变化对试样荷载-加口张开度关系曲线以及破坏行为的影响。结果表明，考虑岩石材料各项物理力学指标的空间相关尺度特征对评价其力学指标的离散性以及破坏形态特征有着较显著的影响。

A mesomechanical model with spatial correlation scale character and its application

Natural rocks show highly heterogeneous character on the micro-and meso-scales due to the randomly distributed defects.Based on the continuum mechanics framework,a scalar damage model is presented for simulating the deformation and failure process of rock material on the meso-scale.A spatial correlation scale factor is developed into the conventional Weibull random distribution model such that the spatial correlation characters of the physico-mechanical indices of rock material can be considered in numerical model.A series of uniaxial tensile tests on sandstone are chosen for parametric analyses aiming for investigation into the influence of spatial correlation scale factor in the random field on the load-cut opening degree curves and failure behavior.The modeling results demonstrate that the value of the spatial correlation scale factor for physico-mechanical indices of rock material can significantly influence the evaluation of mechanical parameters as well as the damage and failure pattern.