基于加载速率效应的煤样损伤演化研究  

Study on damage evolution of coal samples based on loading rate effect

作　　者：李庆文 高森林 黄筱 LI Qingwen;GAO Senlin;HUANG Xiao(School of Civil and Architectural Engineering,Liaoning University of Technology,Jinzhou 121000,China)

机构地区：[1]辽宁工业大学土木建筑工程学院,辽宁锦州121000

出　　处：《煤矿安全》2023年第11期105-115,共11页Safety in Coal Mines

基　　金：国家自然科学基金资助项目(51704144);辽宁省博士科研启动基金资助项目(2019-BS-120);辽宁省自然科学基金指导资助项目(20180550297)。

摘　　要：为了明确加载速率对煤样损伤行为的影响,利用SAM-2000岩石力学试验系统进行不同加载速率下单轴压缩试验,分析了破坏形态、应力—应变、弹性模量、峰值应力和峰值应变等随加载速率的变化规律;推导了能量损伤本构模型,并验证本构模型的合理性。研究结果表明:煤样在压缩破坏过程中可分为压密、弹性、屈服和破坏4个阶段,煤样呈现剪切破坏;随着加载速率的变化,峰值强度和加载速率呈正相关;弹性模量初始呈现近70°的线性增长,后缓慢增加;峰值应变随着加载速率的增加先呈现出减小而后增大趋势;煤样的弹性能、耗散能随着加载速率的增大表现出线性增长的关系,比吸能随加载速率增大而增大,峰值应力前主要以弹性能为主,耗散能为辅,破坏阶段反之;加载速率不会影响煤样能量转化规律趋势和损伤破坏过程。In order to clarify the influence of loading rate on the damage behavior of coal samples,the uniaxial compression tests of heterogeneous coal samples under different loading rates were carried out based on SAM-2000 rock mechanics test system,and the variation of the failure morphology,stress-strain,elastic modulus,peak stress and peak strain with loading rates were analyzed;the energy damage constitutive model was derived and the rationality of the constitutive model was verified.The study result shows that coal samples can be divided into four stages during the compressive failure process:compaction stage,elastic stage,plastic stage and failure stage;with the change of loading rate,peak strength is positively correlated with loading rate.Elastic modulus firstly increases approximately 70°linearly,and then gradually decreases slowly.With the increase of loading rate,the peak strain of coal pillars first decreases and then increases;the elastic energy and dissipation energy of coal samples show a linear increase with the increase of loading rate.And the specific energy absorption increases with the increase of loading rate.Before the peak stress,the elastic energy is mainly dominated,and the dissipation energy is supplemented,and the failure stage is the opposite.The trend of energy conversion and the damage process of coal samples will not be influenced by loading rates.

关 键 词：煤样 加载速率 单轴压缩 能量耗散 本构关系 

分 类 号：TD313[矿业工程—矿井建设]