不同应变率下岩-煤-岩组合体冲击动力试验研究  

Impact dynamic testsfor rock-coal-rock combination under different strain rates

作　　者：苗磊刚[1,2] 牛园园 石必明[1] MIAO Leigang;NIU Yuanyuan;SHI Biming(School of Mining and Safety Engineering,Anhui University of Science and Technology,Huainan 232001,China;College of Energy and Transportation Engineering,Jiangsu Vocational Institute of Architectural Technology,Xuzhou 221116,China;College of Rail Transit,Jiangsu Province Xuzhou Technician Institute,Xuzhou 221151,China)

机构地区：[1]安徽理工大学能源与安全学院,安徽淮南232001 [2]江苏建筑职业技术学院能源与交通工程学院,江苏徐州221116 [3]江苏省徐州技师学院轨道交通学院,江苏徐州221151

出　　处：《振动与冲击》2019年第17期137-143,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(51474010);住房和城乡建设部资助项目(2016-R3-021);江苏省自然科学基金(BK20160208);江苏省高等学校自然科学研究项目资助;江苏省高校“青蓝工程”资助项目

摘　　要：为了研究岩-煤-岩组合体动态力学性质,利用直径为75 mm的分离式霍普金森压杆(SHPB)在5种不同应变率下对组合体试件进行单轴动态冲击压缩试验。研究结果表明:气压与子弹速度之间、冲击速度与应变率之间、应变率与动态弹性模量之间、应变率与动态抗压强度之间、应变率与分维数值之间都近似呈线性关系;σ-ε曲线在近似直线上升到峰值应力的75%左右时,随着应力的增加,曲线斜率逐渐降低,直至达到应力峰值,试件破碎后,呈现跳崖式下降现象;岩-煤-岩组合体在应变率较低时沿着加载方向轴向劈裂破坏,但伴随着应变率的升高,岩块分布也逐渐呈现细粒化,破碎程度也随之增强,块度分维数值也呈线性升高。Here,in order to study dynamic properties of a rock-coal-rock combination,uniaxial dynamic impact compression tests were conductedfor the combination specimen using a split Hopkinson pressure bar(SHPB)with diameter of 75 mm under 5 different strain rates.The results showed that relations between air pressure and bullet velocity,bullet velocity and strain rate,strain rate and dynamic elastic modulus,strain rate and dynamic compressive strength as well as strain rate and fractal dimension areapproximately linear,respectively;when the specimen’sσ-εcurve rises almostlinearly to about 75%of peak stress,with increase in stress,the curveslope gradually decreases until reaching peak stress;after the specimen is broken,the curve hasa precipice-like descent;the rock-coal-rock combination splits axiallyin loading direction during lower strain rate;but with increase in strain rate,distributionof rock blocks is gradually fine-grained;with increase in its broken degree,rock block fractal dimension rises linearly.

关 键 词：岩-煤-岩组合体 应变率 分离式霍普金森压杆 动态力学 分维数 

分 类 号：TD315[矿业工程—矿井建设]