基于均匀化方法给出低孔隙率脆性岩石在热-力耦合荷载作用条件下的各向异性损伤模型和有效热传导特性模型。其中,损伤模型可考虑非等温条件下裂纹的法向压缩变形、刚度恢复以及裂纹的滑动剪胀特性,热传导特性模型可反映损伤过程中细观结构的演化以及裂纹形态、孔隙率和饱和度变化对岩石有效热传导特性的影响。讨论低孔隙率结晶岩裂纹形态和饱和度对其有效热传导特性的影响;采用瑞典sp闪长岩在三轴压缩条件下的应力-应变曲线验证损伤模型的有效性,并分析岩石在损伤演化过程中裂纹体积率、密度、形态、饱和度和有效热传导特性的演化规律。研究成果对于深部岩体的热-力耦合特性研究具有一定参考意义。
An anisotropic damage model and an effective thermal conductivity model were presented based on homogenization techniques for low-porosity brittle rocks subjected to mechanical and thermal loadings.The thermal effect,the recovery of normal stiffness and the mobilized dilatancy behavior were incorporated in the damage model.The thermal conductivity model took into account the effects of damage-induced microstructure evolution,crack shape,porosity and saturation degree on the effective thermal conductivity of brittle rocks.The influences of crack shape and saturation degree on the effective thermal conductivity of low-porosity crystallized rocks were particularly discussed.The damage model was validated by the triaxial test data on an intact ?sp? diorite;and the evolutions of porosity,crack density,crack shape,saturation degree and the effective thermal conductivity during the mechanical loading were demonstrated.The results may provide a helpful reference for better understanding the coupled thermo-mechanical behaviors of deep rocks.