• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
含水煤样动态拉伸能量演化与破坏特征试验研究
  • Title

    Research on dynamic tensile energy evolution and fractal characteristics of water bearing coal samples

  • 作者

    杨科魏祯窦礼同池小楼刘文杰张继强

  • Author

    YANG Ke,WEI Zhen,DOU Litong,CHI Xiaolou,LIU Wenjie,ZHANG Jiqiang

  • 单位

    安徽理工大学 深部煤矿采动响应与灾害防控国家重点实验室 安徽理工大学 煤矿安全高效开采省部共建教育部重点实验室

  • Organization
    Anhui University of Science and Technology,State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine,Huainan; Anhui University of Science and Technology,Key Laboratory of the Ministry of Education for Safe and Efficient Coal Mining
  • 摘要

    为研究不同含水煤样动态拉伸变形破坏过程的能量耗散规律,利用分离式霍普金森压杆(SHPB)试验系统,对不同含水煤样进行冲击加载下的动态劈裂试验,并结合超高速数字图像相关(DIC)试验系统对煤样动态拉伸破坏过程进行观测。基于试验结果分析,获得了煤样破坏过程能量耗散特性随含水率的变化规律,分析了含水率对破碎煤样分形维数的影响。研究结果表明,冲击载荷下应力波是煤样内部大量微损伤结构及原生孔隙、空隙损伤演化的主控因素,煤岩体破碎是一个能量吸收与耗散的过程,随着冲击载荷的增加煤样耗散能密度呈线性增大,但当入射能较小时煤样耗散能密度值相差不大;试样分形维数随加载气压的增加而增加,且增加速率有减小趋势,同种加载气压下,饱和煤样的分形维数最大,干燥煤样的最小;煤样破坏主要以拉伸劈裂为主,破坏裂纹沿加载方向发育,率先在圆盘中部起裂,随后萌生多条次生裂纹,次生裂纹随加载气压的增大而增多,低加载气压下,劈裂裂纹在煤样中的扩展时间较长,扩展速度较慢;基于数字图像技术发现冲击载荷下饱和煤样中部出现多个主应变集中域,且范围逐渐扩大最终沿径向发育贯通。

  • Abstract

    In order to study the energy dissipation law of dynamic tensile deformation and failure process of coal samples with different water content,the split Hopkinson pressure bar (SHPB) test system was used to carry out the dynamic splitting test of different water bearing coal samples under impact loading,and the dynamic tensile failure process of coal samples was observed with ultra high speed digital image correlation (DIC) test system.Based on the analysis of the test results,the change law of energy dissipation characteristics of coal samples with moisture content in the failure process was obtained,and the influence of moisture content on the fractal dimension of broken coal samples was analyzed.The results show that the stress wave is the main control factor of the damage evolution of a large number of micro damage structures and primary pores and voids in coal samples under impact load.The coal and rock mass fracture is a process of energy absorption and dissipation.With the increase of impact load,the dissipated energy density of coal sample increases linearly,but when the incident energy is small,the value of dissipated energy density of coal sample has little difference.The fractal dimension of coal sample changes with loading.Under the same loading pressure,the fractal dimension of saturated coal sample is the largest,while that of dry coal sample is the smallest.The main failure mode of coal sample is tensile splitting,and the failure crack develops along the loading direction,with the first cracks in the middle of the disc,and then multiple secondary cracks are initiated,which increase with the increase of loading pressure.Based on digital image technology,it is found that there are many main strain concentration regions in the middle of saturated coal sample under impact load,and the range gradually expands,and finally develops and penetrates along the radial direction.

  • 关键词

    动态拉伸分离式霍普金森压杆(SHPB)能量耗散数字图像相关法(DIC)分形维数

  • KeyWords

    dynamic stretching;split Hopkinson pressure bar(SHPB);energy dissipation;digital image correlation(DIC);fractal dimension

  • 引用格式
    杨科,魏祯,窦礼同,等.含水煤样动态拉伸能量演化与破坏特征试验研究[J].煤炭学报,2021,46(2):398-411.
    YANG Ke,WEI Zhen,DOU Litong,et al.Research on dynamic tensile energy evolution and fractal characteristics of water bearing coal samples[J].Journal of China Coal Society,2021,46(2):398-411.
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