基于缺陷生长的岩石应变软化损伤本构模型研究  

A new strain softening damage constitutive model for rocks based on defects growth

作　　者：刘冬桥[1] 李东[1,2] 张晓云 

机构地区：[1]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083 [3]绍兴文理学院土木工程学院,浙江绍兴312000

出　　处：《岩石力学与工程学报》2017年第A02期3902-3909,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划专项资助项目(2016YFC0600901);国家自然科学基金资助项目(51704298);北京市共建专项资助项目(80044810)~~

摘　　要：从损伤角度分析岩石压缩变形过程微裂隙的演化特征,结果表明:岩石压缩变形过程可划分为弹性恢复、损伤保持、损伤开始、损伤加速和损伤变缓五个阶段。借助应变等效理论的"弹性模量法",进一步研究岩石损伤演化规律。在此基础上,从岩石微元角度,建立基于岩石缺陷生长的损伤本构模型,实现对岩石损伤全过程统一、完整的描述。该模型仅用一个简单函数实现对应力–应变全过程的描述,且参数少、物理意义明确。试验数据与理论曲线比较,具有很好的一致性,说明了该模型的合理性。The defects evolution characteristics in the complete deformation process of rocks are analyzed,the results show that the stress-strain curves of rocks can be divided into five stages including elasticity recovery,damage retaining,damage initiation,damage acceleration and damage slow-down.Based on the＂elastic modulus method＂derived from the hypothesis of strain equivalence,damage evolution law is further studied.And a defects grown model is proposed based on the hypothesis of rock micro unit,and it can describe the complete damage evolution process well.Then a damage constitutive model is developed.This model can describe the complete deformation process of rocks satisfactorily.The used mathematical function is simple with just four model parameters,and each parameter has distinct physical meaning.Finally,the theoretical results fit very well with the test results in relevant references,which indicate the rationality of this model.

关 键 词：岩石力学 压缩试验 缺陷生长 应变软化 损伤演化 本构模型 

分 类 号：TU45[建筑科学—岩土工程]