考虑时效损伤劣化的变参数非线性蠕变损伤模型

发布时间：2018-01-26 06:43

本文关键词： 稳定蠕变损伤因子损伤元件时效-非线性蠕变损伤模型　出处：《工程力学》2017年06期 　论文类型：期刊论文

【摘要】：应力长期作用下岩体内部损伤不断累积、扩展,导致部分承载单元丧失承载能力,使得岩体内部真实应力强度大于表观应力。该文以流变学理论为基础,将损伤因子引入弹性元件及黏性元件中,给出弹性损伤元件及黏性损伤元件的蠕变特征方程,用以描述持荷过程中由于损伤累积而呈现出蠕变与时间相关的非线性变形特征;然后以弹性损伤元件及黏性损伤元件的蠕变特征方程为基础,给出考虑损伤效应的经典组合模型的蠕变状态方程,并依据稳定蠕变过程中蠕变变形的组成特征,构建了用于描述软岩稳定蠕变的五元件变参数非线性蠕变损伤模型,同时给出了蠕变损伤组合模型的蠕变变形特征方程;最后以江西东乡铜矿砂质页岩稳定蠕变阶段实验数据为基础,分析并验证了蠕变损伤模型在描述软岩非线性蠕变特征方面的准确性及适用性,拟合结果表明:引入损伤因子的蠕变模型元件,能够很好的描述蠕变的时效-非线性特征。
[Abstract]:Under the long-term action of stress, the internal damage of rock mass accumulates and expands, which results in the loss of bearing capacity of part of the bearing unit, which makes the real stress intensity of rock mass larger than the apparent stress. This paper is based on rheological theory. The creep characteristic equation of elastic damage element and viscous damage element is given by introducing the damage factor into elastic element and viscous element. It is used to describe the creep and time dependent nonlinear deformation characteristics due to damage accumulation in the process of load holding. Then based on the creep characteristic equation of elastic damage element and viscous damage element, the creep state equation of classical composite model considering damage effect is given, and the constitutive characteristics of creep deformation during steady creep process are given. A five-element nonlinear creep damage model with variable parameters is constructed to describe the creep stability of soft rock, and the creep deformation characteristic equation of the creep damage combined model is given. Finally, the accuracy and applicability of creep damage model in describing nonlinear creep characteristics of soft rock are analyzed and verified based on the experimental data of stable creep stage of Dongxiang copper ore shale in Jiangxi province. The fitting results show that the creep model element with damage factor can well describe the time-nonlinear characteristics of creep.
【作者单位】：南华大学核资源工程学院;中南大学资源与安全工程学院;武汉理工大学资源与环境工程学院;
【基金】：国家自然科学基金项目(51404179) 南华大学校级创新团队计划项目(NHCXTD04) 南华大学博士启动基金项目(2014XQD09)
【分类号】：TU45
【正文快照】： 岩石的流变性是指岩石在力、温度、辐射等条件下呈现的与时间有关的变形、流动和破坏等性质,即时间效应[1]。1948年,陈宗基开辟了国内岩石流变学研究的先河,并以流变学的基本观点对各种岩石力学问题进行了一系列的研究工作[2]。在岩石流变实验与理论研究工作中,基于基本流变元

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