单轴拉伸条件下岩石本构理论研究  

A study of complete stress-strain relation for mesoscopic heterogenous rocks under uniaxial tensile loading

作　　者：周小平[1] 张永兴[1] 朱可善[1] 

机构地区：[1]重庆大学土木工程学院,重庆400045

出　　处：《岩土力学》2003年第S2期143-147,共2页Rock and Soil Mechanics

摘　　要：利用损伤力学理论研究了细观非均匀性岩石拉伸应力应变关系,包括:线弹性阶段、非线性强化阶段、应力降阶段、应变软化阶段。所用的模型分析了岩石的细观各向异性对全过程应力应变关系的影响,分析了产生应力跌落和应变软化的主要原因是损伤和变形局部化,将损伤和变形局部化引入本构模型是和以往模型的重要区别。通过与实验成果对比分析验证了模型的正确性和有效性。On the basis of mesomechanics, the complete stress-strain relation including linear elasticity, non-linear hardening, rapid stress drop and strain softening is obtained. The influence of all microcracks with different sizes and orientations are introduced into the constitutive relation by using the probability density function describing the distribution of orientations p() and the probability density function describing the distribution of sizes p(c). The influence of Weibull distribution describing the distribution of orientations p() and Rayleigh function describing the distribution of sizes p(c) on the constitutive relation are studied. The behaviour of rapid stress drop and strain softening are due to localization of deformation and damage. Theoretical predictions have shown to be consistent with the experimental results.

关 键 词：拉应力 细观非均匀性 损伤力学 损伤和变形局部化 应力-应变全过程 

分 类 号：TU452[建筑科学—岩土工程]