循环冲击荷载作用下煤岩组合体力学响应和能量耗散特征研究  

A study on the mechanical response and energy dissipation characteristics of coal-rock composite under cyclical impact loads

作　　者：杨科[1,2] 郑诗章 刘文杰 许日杰[1,2] 张寨男 刘帅 池小楼 YANG Ke;ZHENG Shizhang;LIU Wenjie;XU Rijie;ZHANG Zhainan;LIU Shuai;CHI Xiaolou(Key Laboratory of Miming Coal Safety and Efficiently Constructed by Anhui Province and Mimistry of Education,Anhui University of Science&Technology,Huainan 232001,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science&Technology,Huainan 232001,China;Department of Environment,Land and Infrastructure Engineering,Politecnico di Torino,Torino 10129,Italy)

机构地区：[1]安徽理工大学煤矿安全高效开采省部共建教育部重点实验室,安徽淮南232001 [2]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001 [3]都灵理工大学环境、土地和基础设施工程学院,都灵10129

出　　处：《振动与冲击》2024年第20期150-161,共12页Journal of Vibration and Shock

基　　金：国家自然科学基金区域创新发展联合基金(U21A20110)。

摘　　要：为探究循环冲击下煤岩组合体的力学响应与能量耗散特征,采用分离式霍普金森压杆试验系统,设计开展5种不同冲击速度的煤岩组合体循环冲击压缩试验,对比分析不同冲击速度下组合体动态应力应变关系、能量耗散特性和破坏特征。研究结果表明:循环冲击下煤岩组合体存在明显的临界效应,冲击速度低于临界速度时动态抗压强度在冲击前期迅速降低,峰值应变变化率随冲击速度增加而降低;循环冲击下试件总吸收能和分形维数逐渐增大,在临界速度时达到峰值,超过临界速度后两者皆降低;冲击速度超过临界速度后,总吸收能相同时循环冲击条件下煤岩体破坏程度高于单次冲击;当煤岩强度比为1∶2时,随着总吸收能的增加,岩体从积聚和传递能量作用转向于加剧组合体破坏;冲击作用下组合体呈张拉劈裂破坏,低速条件下宏观裂纹萌发主要发生在远离胶结面的煤体端面,随着冲击速度增大远离胶结面岩体一侧亦有裂纹出现,根据失稳发生区域组合体破坏类型分为煤体失稳型和组合体失稳型,循环冲击下均发生组合体失稳型破坏。研究结果为软弱岩层动压巷道与采场围岩稳定性控制提供基础研究。In order to investigate the mechanical response and energy dissipation characteristics of coal-rock composite specimens under cyclic impact,a split Hopkinson pressure bar experimental system was employed.Five different impact velocities were designed for cyclic impact compression experiments on coal-rock composite specimens.Comparative analyses were conducted to examine the dynamic stress-strain relationships,energy dissipation characteristics,and failure features of the composite specimens at different impact velocities.The results indicate that under cyclic impact,coal-rock composite specimens exhibit pronounced critical effect.When the impact velocity is below the critical velocity,the dynamic compressive strength rapidly decreases in the early stage of the impact,and the rate of change in peak strain decreases with impact velocity.During cyclic impact,the total absorbed energy and fractal dimension of the specimens gradually increase,reaching their peak values at the critical velocity,after which both parameters decrease.Beyond the critical velocity,under equivalent total absorbed energy,the degree of damage to coal-rock formations under cyclic impact is higher than that under a single impact.With a coal-rock strength ratio of 1∶2,as the total absorbed energy increases,the rock transitions from accumulating and transmitting energy to intensifying composite body damage.Under impact,the composite body exhibits tensile and splitting failure.Under low-speed conditions,macroscopic cracks mainly initiate at the coal body end face far from the bonding surface.As the impact velocity increases,cracks also appear on the side of the rock away from the bonding surface.According to the region of instability,the failure types of the composite body are classified into coal body instability and composite body instability,and under cyclic impact,the composite body exhibits composite body instability failure.The results provide a fundamental basis for the stability control of dynamic pressure roadways and surrounding rock in

关 键 词：循环冲击 煤岩组合体 动力学特性 能量耗散 分形维数 裂纹扩展 

分 类 号：TD315[矿业工程—矿井建设]