摘要
采用自行研制开发的单双向约束摆锤式冲击动力加载试验装置,并配合超声波检测设备,分别进行单向和双向约束条件下,冲击荷载对煤样渐进破坏规律的系统试验研究,分析煤样在不同循环冲击直至形成宏观破坏的整个过程中表现出的破坏特征与能量耗散规律。结果表明:随着冲击次数的增加,煤样损伤量表现为倒"S"型累积增长模式;在单向约束条件下,当轴向应力为1 MPa时煤样累积损伤最大,随着轴向应力提高,煤样损伤量显著减小;而在双向约束条件下,当水平约束与轴向约束应力比为1∶1时,此时煤样最不容易发生损伤,保持水平约束应力不变,并逐渐增大轴向应力,煤样在试验初期就会出现损伤加剧,最终损伤量明显变大;并从能量耗散角度对煤样渐进破坏的规律进行了分析,给出2种情况下发生损伤破坏的能量判据。
A systematic impact load test on the progressive failure of briquette coal under unilateral and biaxial constraints was conducted by using the restraint pendulum impact dynamic loading test device and the ultrasonic testing device,and destruction characteristics and energy dissipation law of coal samples during the impact process of different cycles until macro damage was analyzed. The results show that the damage of the samples increases in an inverted S form with the impact number. Under the unilateral constraint condition,the cumulative damages of the samples are the largest when the axial stress is 1 MPa,and with increasing the axial stress,the damage is greatly reduced. For the biaxial constraint condition,however,the coal sample is least likely to occur damage when both the horizontal constraint and the axial constraint stresses are 1 MPa. In the case of that the horizontal restraint stress remains unchanged and the axial stress increases gradually,the samples would be damaged significantly,especially at the final period. The evolution of progressive destruction of coal samples is explained from the aspect of energy dissipation,and the energy criterions of damage and destruction for two cases are given.
作者
赵洪宝
吉东亮
李金雨
王涛
刘一洪
ZHAO Hongbao;JI Dongliang;LI Jinyu;WANG Tao;LIU Yihong(School of Energy and Mining Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2021年第1期53-64,共12页
Chinese Journal of Rock Mechanics and Engineering
基金
越崎杰出学者资助项目(800015Z1179)
国家自然科学基金资助项目(51474220)
中央高校基本科研业务费研究生科研创新能力提升项目(2020YJSNY07)。
关键词
岩石力学
单双向约束
冲击荷载
损伤量
能量耗散
rock mechanics
unilateral and biaxial constraints
impact load
damage degree
energy dissipation
