摘要
为了探究加载速率对非均质煤样力学响应的影响,基于SAM-2000岩石力学试验系统,开展了不同加载速率下非均质煤样单轴压缩试验。结果表明:随加载速率增加,煤样飞溅煤屑尺度越大、飞溅距离越远、完整性越差、能量释放程度越猛烈,属于劈-剪复合型破坏形态;峰值强度、弹性模量均随加载速率增加而先近似垂直骤增后再平稳增加,均满足有理函数Rational5关系;峰值应变先快速降低后逐渐趋于平稳,满足衰减指数函数关系;峰值点总能量随加载速率增加,先近似垂直骤增后再平稳减小,弹性能先近似垂直骤增后再平稳增加,两者变化规律均满足有理函数Rational 5关系;耗散能随加载速率增加产生2个拐点,先以近似垂直骤降至第1拐点后再近似垂直陡升至第2拐点,再快速减小;比吸能随加载速率增加先近似垂直陡增至拐点后,接着快速下降,再平缓减小;峰值时弹性能占比均高于破坏时弹性能占比,且两者之间至少相差40.12%,峰值时总能量以弹性能为主、耗散能为辅,破坏时反之亦然;推导了不同加载速率下煤样能量耗散损伤本构关系,且拟合度高。
In order to explore the influence of loading rate on the mechanical response of heterogeneous coal samples,the uniaxial compression tests of heterogeneous coal samples under different loading rates were carried out based on SAM-2000 rock mechanics test system.The results show that with the increase of loading rate,the larger the size of the coal dust splashes,the farther the splashes distance,the worse the integrity and the more violent the energy release degree of the coal sample,which belongs to the split-shear composite failure mode.The peak strength and elastic modulus both increase approximately vertically and then increase steadily with the increase of the loading rate,and satisfy the Rational5 relation of the rational function.The peak strain first decreased rapidly and then gradually became stable,satisfying the attenuation exponential function.With the increase of the loading rate,the total energy at the peak point firstly increase approximately vertically and then decreases steadily,and the elastic energy firstly increase approximately vertically and then increases steadily,both of which meet the rational function Rational5 relation.With the increase of loading rate,the dissipation energy produces two inflection points.It drops to the first inflection point approximately vertically and then rises to the second inflection point approximately vertically and then decreases rapidly.With the increase of loading rate,the specific energy absorption first increases vertically to the inflection point,then decreases rapidly,and then gently decreases.The proportion of elastic energy at peak is higher than that at failure,and the difference between the two is at least 40.12%.At the peak,the total energy is dominated by elastic energy,supplemented by dissipative energy,and vice versa at failure;Constitutive relations of energy dissipation damage of coal samples under different loading rates are derived with high fitting degree.
作者
李庆文
高森林
胡露露
禹萌萌
刘艺伟
曾杏钢
祝青云
曹行
黄筱
LI Qingwen;GAO Senlin;HU Lulu;YU Mengmeng;LIU Yiwei;ZENG Xinggang;ZHU Qingyun;CAO Hang;HUANG Xiao(School of Civil and Architectural Engineering,Liaoning University of Technology,Jinzhou 121001,China;School of Civil Engineering,Liaoning Technical University,Fuxin 123000,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2022年第S01期90-102,共13页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51774166,51704144)
辽宁省博士科研启动基金资助项目(2019-BS-120)
关键词
加载速率
非均质煤样
单轴压缩试验
能量耗散损伤
本构关系
loading rates
heterogeneous coal samples
uniaxial compression tests
energy dissipation damage
constitutive relation
作者简介
李庆文(1987—),男,辽宁绥中人,讲师,硕士生导师,博士。E-mail:lgjzlqw@163.com
