不同加载速率下类煤岩力学特性及损伤演化规律研究

发布时间：2018-03-07 01:10

本文选题：煤岩破坏　切入点：煤岩变形　出处：《煤炭科学技术》2017年10期 　论文类型：期刊论文

【摘要】：为研究加载速率对试件强度、变形以及破坏形式的影响,利用刚性试验机对类煤岩试件进行了不同加载速率的单轴压缩试验。借助于颗粒离散元程序PFC建立了煤岩平行黏结颗粒模型,并对不同加载速率下试件内部损伤破裂的声发射信息进行了实时记录;基于数值模型的声发射信息建立了煤岩损伤演化方程。结果表明:随着加载速率的增大,试件单轴抗压强度增大,并且试件破坏形态从多宏观断裂面的Ⅹ形、V形、Y形向单一宏观断裂面转变,整体破碎程度降低;随着加载速率的增大,试件变形破裂过程中,应力峰值附近的声发射率明显升高,表现出声发射活动更为剧烈;试件损伤演化过程基本上分为初始损伤阶段、损伤稳定发展阶段和损伤迅速发展阶段,加载速率对损伤演化的影响主要集中于损伤稳定发展阶段,即加载速率越大,试件越早进入损伤稳定发展阶段。
[Abstract]:In order to study the effect of loading rate on the strength, deformation and failure form of the specimen, Uniaxial compression tests of coal-like rock specimens at different loading rates were carried out by means of a rigid testing machine. A model of coal and rock parallel bonding particles was established by means of particle discrete element program (PFC). The acoustic emission information of the internal damage and rupture of the specimen under different loading rates is recorded in real time, and the evolution equation of the damage of coal and rock is established based on the acoustic emission information of the numerical model. The results show that with the increase of the loading rate, the damage evolution equation of coal and rock is established. The uniaxial compressive strength of the specimen increases, and the failure mode of the specimen changes from X shape V shape and Y shape of the multi-macro fracture surface to the single macro fracture surface, and the whole fracture degree decreases, and with the increase of the loading rate, the specimen deformation and rupture process, The acoustic emission rate near the peak stress increases obviously, which shows that the acoustic emission activity is more intense, the damage evolution process of the specimen is basically divided into the initial damage stage, the damage stable development stage and the damage rapid development stage. The effect of loading rate on damage evolution is mainly focused on the stage of damage stability development, that is, the higher the loading rate, the earlier the specimen enters the stage of damage stability development.
【作者单位】：山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地;山东科技大学矿业与安全工程学院;北京科技大学土木与资源工程学院;
【分类号】：TD313

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