基于能量耗散和声发射的岩石损伤本构模型

为了更好地研究单向受载下岩石的本构关系和损伤演化规律,利用泥岩的单向压缩和声发射试验,分析了岩石的变形特点、能量转化和声发射特征,在此基础上,分别建立考虑能量耗散和声发射的损伤演化方程,提出初始损伤和临界损伤的定义,构建了能够反映岩石压密过程和残余强度阶段的损伤本构模型,并通过单向压缩试验结果对比分析了两种损伤演化规律及理论损伤本构关系。研究结果表明,两种损伤演化规律基本一致,都经历损伤缓慢增加、加速增加和残余损伤3个阶段;材料参数分别影响应力强化、软化和整体应力-应变曲线;两种理论损伤本构关系均较好地反映了岩石的单向受载变形特征,从而证明了所建损伤本构模型符合实际。

Constitutive Model of Rock Damage Based on Energy Dissipation and Acoustic Emission

In order to study the constitutive relation and the damage evolution law of rock under uniaxial loading, the deformation characteristics, energy conversion and acoustic emission characteristics were analyzed using uniaxial compression and acoustic emission test of mudstone. On the basis, the damage evolution equation for energy dissipation and acoustic emission was established respectively,the definition of initial damage and critical damage were proposed, the damage constitutive reflecting the compression process and the residual strength process was constructed, the comparison of two damage evolution laws and theoretical constitutive equations was analyzed by the results of uniaxial compression and acoustic emission test. The results show that the two damage evolution processes are basically identical, and can be divided into three phases, including the stage of damage slow development,the stage of damage accelerating development, and the stage of residual damage. The material parameters have effects on stress strengthening, softening and the whole stress-strain curve respectively. The two theoretical constitutive equations reflect the deformation characteristics of rock under uniaxial loading well; it is proved that the damage constitutive model conforms to the reality.