Analysis of the Localization of Damage and the Complete Stress-Strain Relation for Mesoscopic Heterogeneous Brittle Rock Subjected to Compressive Loads
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摘要: 利用摩擦弯折裂纹模型研究了受压条件下细观非均匀性岩石的损伤局部化问题和全过程应力应变关系.模型考虑了裂纹相互作用对损伤局部化和全过程应力应变关系的影响,确定了损伤局部化发生的条件,分析了产生损伤局部化的原因.研究表明全过程应力应变关系包括线弹性阶段、非线性强化阶段、应力降和应变软化阶段.通过和实验对比分析验证了模型的正确性和有效性.Abstract: A micromechanics-based model is established.The model takes the interaction among sliding cracks into account,and it is able to quantify the effect of various parameters on the localization condition of damage and deformation for brittle rock subjected to compressive loads.The closed-form explicit expression for the complete stress-strain relation of rock containing microcracks subjected to compressive loads was obtained.It is showed that the complete stress-strain relation includes linear elasticity,nonlinear hardening,rapid stress drop and strain softening.The behavior of rapid stress drop and strain softening is due to localization of deformation and damage.Theoretical predictions have shown to be consistent with the experimental results.
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