岩石类材料损伤局部化分叉  

Localization and bifurcation of geomaterials with damage effect

作　　者：王忠昶[1] 王大国[1] 赵德深[1] 

机构地区：[1]大连大学辽宁省高校复杂结构体系灾害预测与防治重点实验室辽宁大连116622

出　　处：《辽宁工程技术大学学报（自然科学版）》2008年第5期705-708,共4页Journal of Liaoning Technical University (Natural Science)

基　　金：国家自然科学基金资助项目(50574016);辽宁省教育厅基金资助项目(2005058);中国博士后基金(20060400972);大连市科学技术基金资助项目(2007J23JH027)

摘　　要：为获得弹塑性变形时破坏失稳的损伤效应,假定岩石类材料各向同性损伤,将损伤变量与加卸载函数引入不连续分叉方法,考虑损伤时的刚度退化和体积扩容,推导出材料损伤失稳时的最大硬化模量和局部化方向角及其与损伤程度和初始泊松比的关系,在平面应力与应变条件下对单轴拉伸压缩试件的分叉失稳进行对比分析。结果表明:局部化方向角与最大硬化模量依赖于材料的初始泊松比与损伤程度;平面应力或应变时,拉伸与压缩得到的局部化方位角之和为90°,最大硬化模量可分为平面应力与应变条件两种,与单轴拉伸或压缩条件无关。To obtain the damage effect in the process of elasto-plasticity deformation of geomaterials, the isotropic damage loading-unloading function and damage variable is introduced to non-continuous bifurcation, the critical hardening modulus and localized orientation angle with consideration of stiffness degradation and dilatancy are set up. The relationship between localized orientation angle and maximal hardening modulus depended on the degree of damage and initial Poisson＇s ratio of rock is explored. Comparative analyzes are conducted to study the bifurcation of uniaxial tension-compression samples under the conditions of plane stress and plane strain. It is shown that variation of orientation angle of localization and maximum hardening modulus depended on the initial Poisson＇s ratio and degree of damage, the sum of orientation angle under tension and compression conditions is 90° , there are plane stress and plane strain cases of the maximum hardening modulus that is independent of the uniaxial compression and tension.

关 键 词：刚度下降 体积扩容 局部化方向角 最大硬化模量 损伤分叉 

分 类 号：TU425[建筑科学—岩土工程]