高温对煤的动态拉伸力学性能的影响  

Effect of High Temperature on Dynamic Tensile Mechanical Properties of Coal

作　　者：袁琪 韩文梅[1] 郑翔 赵鹏[1] YUAN Qi;HAN Wenmei;ZHENG Xiang;ZHAO Peng(School of Aerospace Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学航空宇航学院,山西太原030051

出　　处：《中北大学学报(自然科学版)》2025年第2期197-207,共11页Journal of North University of China(Natural Science Edition)

基　　金：煤与煤层气共采国家重点实验室基金(2022KF10)。

摘　　要：深部煤矿的开采往往受到高温地热及爆破冲击等不利影响,为保证安全生产和提高开采效率,研究温度对煤的动态力学性能的影响至关重要。本研究利用分离式霍普金森杆(SHPB)系统对煤样进行巴西劈裂试验,并结合X射线衍射技术(XRD)和颗粒流程序(PFC)仿真,研究了不同温度、不同加载速率下煤的力学性能和破坏演化过程,同时对其微晶结构及断裂模式进行了分析。试验结果显示:高温使得煤发生劣化,煤样的抗拉强度和与耗散能随温度的升高而减小。抗拉强度、入射能与耗散能随冲击速度的增大而增大,且热处理后煤样的速率依赖性减弱。加热使得煤的层间距减小,堆叠高度增大,有向高阶煤发展的特征。热处理增强了煤的晶体结构有序性,但是微晶尺寸小,水分蒸发和热膨胀不均匀产生的微孔和裂纹对强度的削弱作用更大。PFC模拟煤样动态拉伸过程中,沿着加载方向的主裂纹为拉伸劈裂,两端的楔形区域破碎的类别主要为压剪破坏,拉伸裂纹数量远多于剪切裂纹数量。The mining of deep coal mines is often adversely affected by high temperature geothermal and blasting shocks.In order to ensure safe production and improve mining efficiency,it is very important to study the influence of temperature on the dynamic mechanical properties of coal.In this study,split Hop-kinson bar(SHPB)system was used to carry out Brazilian splitting test of coal samples,and combined with X-ray diffraction(XRD)and particle flow program(PFC)simulation,the mechanical properties and failure evolution process of coal at different temperatures and loading rates were studied,and its microcrys-tal structure and fracture mode were analyzed.The test results show that the high temperature leads to the deterioration of coal,and the tensile strength and dissipative energy of coal samples decrease with the increase of temperature.The tensile strength,incident energy and dissipated energy increase with the increase of impact velocity,and the rate dependence of coal samples decreases after heat treatment.Heat-ing reduces the interlayer spacing of coal and increases the stacking height,which is characterized by the development of high-order coal.Heat treatment enhances the order of the crystal structure of coal,but the microcrystal size is small.Micropores and cracks caused by uneven water evaporation and thermal expan-sion play a greater role in weakening the strength.When PFC simulates the dynamic tensile process of coal samples,the main crack along the loading direction is tensile splitting,the type of fracture in the wedge-shaped region at both ends is mainly compression-shear failure,and the number of tensile cracks is much more than that of shear cracks.

关 键 词：高温劣化 煤热解 动态拉伸 能量耗散 分离式霍普金森杆 

分 类 号：TD313[矿业工程—矿井建设]