摘要
为研究冲击载荷作用下煤的动态力学特性,采用分离式霍普金森压杆试验系统,通过钢制套筒施加环向约束,对煤样进行不同应变率和不同应力状态冲击压缩试验。研究结果表明:应变率和约束状态对煤样应力应变及破坏模式影响显著,随着应变率提高,被动围压条件下煤样应力应变曲线具有明显的屈服平台,塑性流动增强。应变率在30.4~328.7 s^(-1)范围,径向自由下煤样峰值应力为15.32~69.53 MPa,被动围压条件下煤样峰值应力为15.11~104.46 MPa。当应变率高于100 s^(-1)时,被动围压条件下煤样的峰值应力明显高于径向自由条件。由于套筒约束的被动围压作用,煤样破坏形态呈现为压剪破裂模式,与径向自由条件下破碎特征不同。冲击载荷作用下煤样所受被动围压处于不断变化过程,被动围压随轴压增加而快速增长,两者呈正相关二次函数关系。
Here,to study dynamic mechanical properties of coal impact compression,the split Hopkinson pressure bar(SHPB)test system was used to conduct impact compression tests for coal samples under different strain rates and different stress states with steel sleeve to exerting circumferential constraints.The results showed that the strain rate and constraint state have significant effects on coal samples’stress-strain and failure mode;with increase in strain rate,coal samples’stress-strain curve under passive confining pressure has an obvious yield platform,and plastic flow is enhanced;when strain rate is within the range of 30.4-328.7 s^(-1),the peak stress of coal sample under radial free condition is 15.32-69.53 MPa,that under passive confining pressure is 15.11-104.46 MPa;when the strain rate is higher than 100 s^(-1),the peak stress of coal sample under passive confining pressure is obviously higher than that under radial free condition;due to passive confining pressure of sleeve constraint,the failure mode of coal sample is compression-shear fracture mode,it is different from fracture characteristics under radial free condition;under impact load,passive confining pressure of coal sample is in a continuous changing process,it increases rapidly with increase in axial pressure,both of them reveal a positively correlated quadratic function relationship.
作者
焦振华
穆朝民
王磊
崔智丽
袁秋鹏
邹鹏
王炯
JIAO Zhenhua;MU Chaomin;WANG Lei;CUI Zhili;YUAN Qiupeng;ZOU Peng;WANG Jiong(State Key Lab of Mining Response and Disaster Prevention and Control in Deep Coal Mine,Anhui University of Science and Technology,Huainan 232001,China;School of Safety Science and Engineering,Anhui University of Science and Technology,Huainan 232001,China;School of Mechanics and Optoelectronic Physics,Anhui University of Science and Technology,Huainan 232001,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2021年第21期185-193,共9页
Journal of Vibration and Shock
基金
国家重点研发计划(2016YFC0801401)
安徽省自然科学基金青年项目(1908085QE184)
深部煤矿采动响应与灾害防控国家重点实验室自主课题(SKLMRDPC19ZZ04)。
关键词
分离式霍普金森压杆(SHPB)
应变率
被动围压
煤
动态力学特性
split Hopkinson pressure bar(SHPB)
strain rate
passive confining pressure
coal
dynamic mechanical properties