基于双剪统一强度理论的煤岩损伤本构模型  

Damage constitutive model of coal rock based on double-shear unified strength theory

作　　者：罗吉安 何俊 董春亮 李文成 LUO Ji′an;HE Jun;DONG Chunliang;LI Wencheng(School of Mechanics and Optoelectronic Physics,Anhui University of Science&Technology,Huainan 232001,China;School of Civil Engineering and Architecture,Anhui University of Science&Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学力学与光电物理学院,安徽淮南232001 [2]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《长沙理工大学学报（自然科学版）》2022年第2期98-106,共9页Journal of Changsha University of Science and Technology:Natural Science

基　　金：国家自然科学基金资助项目(52074006);安徽省质量工程项目(2020zyrc054);安徽省高校自然科学重点研究项目(KJ2021A0424)。

摘　　要：【目的】通过建立一种分级加卸载本构模型,研究煤岩在高应力作用下的复杂应力-应变关系。【方法】假设煤岩的微元强度服从Weibull概率密度分布,结合双剪统一强度理论,创建煤岩损伤本构模型;利用煤岩试验结果对本构模型进行验证,对试验得到的应力-应变曲线进行拟合,得到参数的演化规律,并对这些参数进行敏感性分析。【结果】随着煤岩加卸载次数的增多,煤岩内部塑性变形逐渐累积,滞回环的面积不断增大;随着加卸载等级的提高,煤岩逐渐硬化,煤岩内部的损伤逐渐增多,煤岩脆性相应增强,煤岩微元强度有所减小,煤岩微元强度分布的集中程度有很大提高。【结论】本研究所建立的基于双剪统一强度理论的煤岩损伤本构模型能够较准确地表达煤岩在分级加卸载条件下的应力-应变关系,具有一定的理论和现实意义。[Purposes]The complex stress-strain relationship of coal rock under high stress is studied by establishing a stepped loading and unloading constitutive model.[Methods]The damage constitutive model of coal rock is established combined with the double-shear unified strength theory,in which the hypothesis that the micro-element strength of coal rock obeys the Weibull probability density distribution is adopted.The constitutive model is validated by using coal rock experiments.Then,the obtained experimental stress-strain curve is fitted to obtain the evolution law of parameters,and the sensitivity analysis of these parameters is carried out.[Findings]During the loading and unloading test of coal rock,the inside plastic deformation of coal rock is gradually accumulated and the area of the hysteresis loop keeps increasing.An increase in loading and unloading level leads to the hardening of coal rock,an increase in the inside damage and brittleness of coal rock,and a decrease in micro-element strength of coal rock.[Conclusions]The damage constitutive model of coal rock based on the double-shear unified strength theory established in this study can accurately express the stress-strain relationship of coal rock under the conditions of stepped loading and unloading,which is of some theoretical and practical significance.

关 键 词：双剪统一强度理论 分级加卸载 损伤本构模型 微元强度 应力-应变关系 

分 类 号：TU457[建筑科学—岩土工程]