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单轴压缩下不同层理煤能量演化及红外辐射特征

Energy evolution and infrared radiation characteristics of different bedded coal under uniaxial compression

  • 摘要: 为了研究不同层理煤变形破坏过程中能量演化及红外辐射响应特征,以红庆河煤矿3-1煤层的煤样为研究对象,开展了4种不同层理角度(0°、30°、60°及90°)单轴压缩试验,并利用红外热成像仪监测煤样变形破坏过程中的红外温度场特征。试验结果表明:随着层理角度的增加,试样的抗压强度及应变能均呈“V”形变化趋势,60°时达到最小值,层理对峰前阶段的弹性应变能Ue及峰后阶段的耗散能Ud影响显著;不同层理角度煤样整体上表现为升温趋势,平均红外温度前兆点为0.84σp;试样破坏模式导致温度变化范围不同,0°和30°试样以张−剪破坏为主,升温幅度分别为1.12、1.30 ℃,而60°试样以单一剪切破坏为主,升温幅度较低为0.46 ℃,90°试样破坏以拉伸破坏为主,升温幅度最低为0.4 ℃;应变能与平均红外辐射温度呈正相关关系,相关程度排序为总应变能U<弹性应变能Ue<耗散能Ud。研究结果可以为煤岩动力灾害预警提供参考。

     

    Abstract: In order to study the energy evolution and infrared radiation response characteristics during the deformation and failure process of coal with different bedding angles, uniaxial compression tests with four different bedding angles (0°, 30°, 60° and 90°) were carried out on a strong burst liability coal samples from 3-1 coal seam of Hongqinghe coal mine. The infrared temperature field characteristics of the coal samples during deformation and damage were monitored using an infrared thermal imaging camera. The test results show that as the bedding angle increases the compressive strength and strain energy of the sample show a “V” shaped trend, reaching the minimum value at 60°. The bedding has a significant impact on the elastic strain Ue in the pre-peak stage and dissipation energy Ud in the post-peak stage; The coal samples showed an overall warming trend with different bedding angles, with an average infrared temperature precursor point of 0.84σp.The bedding structure seriously affects the infrared radiation temperature and the difference of failure patterns lead to different temperature ranges. The 0° and 30° specimens are dominated by shear-tension composite failure, with a high temperature rise of 1.12 and 1.30 ℃, respectively, while the 60° specimen is dominated by single shear failure, with a low temperature rise of 0.46 ℃. The failure of 90° specimen is tensile failure, and the temperature rise is the lowest 0.4 ℃. The strain energy was positively correlated with the mean IR radiation temperature, and the correlation degree was ranked as U<Ue<Ud. The research results can provide reference for early warning of coal dynamic disasters.

     

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