基于对数正态分布的岩石损伤本构模型研究

tudy on Constitutive Model of Rock Damage Based on Lognormal Distribution

根据岩石微元物理力学性能服从随机分布的特点,采用对数正态分布作为岩石微元强度的概率分布模型,结合损伤力学理论和统计强度理论,建立了三轴压缩条件下的岩石损伤本构模型。在此基础上,考虑岩石破裂过程全应力应变曲线的特点,利用多元函数极值理论依据试验曲线的特征参量确定出损伤本构模型参数。与试验结果及前人研究结果比较,该模型形式简单,参数求取容易,能较好地反映岩石内部缺陷分布和变形特征,表征岩石破裂过程的全应力应变关系。

Based on the characteristic of stochastic distribution of the physical and mechanical property of rock micro-unit,the lognormal distribution is chosen as probability distribution model of rock micro-unit strength.Using damage mechanics theory and the statistical strength theory,a damage constitutive model is established under rock triaxial compression test.Moreover,the characteristics of rock stress-strain curve during the full process of rock failure are also considered and the characteristic parameters of the test curve are introduced,these model parameters are determined according to the extreme theory of multivariate function.Contrasted with triaxial compression test results and the existing research results,this model is simple and the model parameters can be easily solved,it can well reflect the intrinsic flaws distribution and deformation property of rock,to characterize the stress-strain relation during the full process of rock failure.