波阻抗对岩石动力学特性影响的模拟试验研究  

Tests for effects of wave impedance on rock’s dynamic performance

作　　者：杨仁树[1,2] 李炜煜[1] 方士正 朱晔[1] 李永亮 郑昌达 YANG Renshu;LI Weiyu;FANG Shizheng;ZHU Ye;LI Yongliang;ZHENG Changda(School of Mechanics and Architecture Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]深部岩土力学与地下工程国家重点实验室,北京100083

出　　处：《振动与冲击》2020年第3期178-185,共8页Journal of Vibration and Shock

基　　金：国家重点基础研究发展计划(2016YFC0600903);高等学校学科创新引智计划“111计划”(B14006)

摘　　要：利用分离式霍普金森压杆(SHPB)试验系统,对系列波阻抗的模型材料进行不同应变率下的冲击压缩试验。试验结果表明:岩石在冲击荷载下的应力波传播特征、动态应力应变关系以及破碎块度分形特征同时受波阻抗、应变率和冲击速度的影响。波阻抗相同时,反射波和透射波信号幅值均随冲击速度增大呈线性增大,同时应变率效应明显,随着应变率的增大:峰值应力呈线性增大,动态弹性模量增大,应变软化阶段延长;破碎程度增大,破碎块度分形维数呈线性增大。应变率相同时,随着波阻抗的减小:反射波幅值增大、透射波幅值减小;峰值应力减小,应变软化阶段延长,塑性段趋于明显,且有塑性流动现象出现;破碎程度增大,破碎块度分形维数增大。同时随着波阻抗减小,应变率增大对动态抗压强度的增大以及对破碎程度的加剧效果减弱,应变率效应减弱,逐渐趋于不明显。A series of impact compression tests were conducted on model materials with different wave impedances under different strain rates using the split-Hopkinson pressure bar(SHPB)test system.The test results showed that under impact load,rock’s stress wave propagation characteristics,dynamic stress-strain relation and fractal features of rock fragmentation are affected by wave impedance,strain rate and impact velocity;when wave impedance is the same,amplitudes of reflected wave and transmitted one increase linearly with increase in impact velocity;at the same time,effect of strain rate is obvious,with increase in strain rate,peak stress increases linearly,dynamic elastic modulus increases,and strain softening stage prolongs;when crushing degree increases,fractal dimension of fragmentations increases linearly;when strain rate is the same,with decease in wave impedance,amplitude of reflected wave increases and transmitted one’s decreases;when peak stress decreases,strain softening stage prolongs,plastic stage tends to be obvious,and plastic flow phenomenon appears;when crushing degree increases,fractal dimension of fragmentations increases;with decrease in wave impedance,effect of increase in strain rate on increase in dynamic anti-compression intensity and enhancing degree of crushing weakens,strain rate’s effect weakens and gradually tends to be unconspicuous.

关 键 词：波阻抗 应变率 分离式霍普金森压杆 应力波 动态力学性能 块度分维 

分 类 号：TU45[建筑科学—岩土工程]