尺寸与形状效应下煤岩组合体力学特性与声发射特征分析

    Analysis of mechanical properties and acoustic emission characteristic of coal-rock assembly under the effect of size and shape

    • 摘要: 为研究尺寸与形状效应下煤岩组合体力学特性和声发射特征的影响规律,对不同尺寸、不同形状的煤岩组合体试件进行单轴压缩试验,利用声发射系统记录不同承载阶段试件内部声发射的振铃计数和能量演化。结果表明:煤岩组合体的强度介于纯煤、纯岩两者的强度之间,纯岩、纯煤、煤岩组合体试件的峰值强度分别为30.3、5.7、9.7 MPa;圆柱组合体和立方组合体的峰值强度都随着宽高比的减小而不断降低,最大降幅分别为52.68%、59.21%;试件声发射振铃计数与能量表现出一致的规律性,均表现出与试件应力同步变化的趋势;圆柱组合体最大振铃计数的出现提前于最大应力值的出现,而立方组合体最大振铃计数滞后于最大应力值的出现。

       

      Abstract: In order to study the influence of the mechanical properties and acoustic emission characteristics of the coal-rock assembly under the effect of size and shape, the uniaxial analysis of coal-rock assembly specimens of different sizes and shapes was carried out, and the acoustic emission system is used to record the ringing count and energy evolution of the internal acoustic emission of the specimen at different loading stages. The results show that the strength of the coal-rock assembly is between that of pure coal and pure rock. The peak strengths of the pure rock, pure coal, and coal-rock assembly specimens are 30.3 MPa, 5.7 MPa, and 9.7 MPa, respectively; the peak intensity of the combination body and the cubic combination body are continuously reduced with the decrease of the aspect ratio, and the maximum reduction amplitude is 52.68% and 59.21% respectively; the acoustic emission ringing count and energy of the specimens show consistent regularity, both of which show the trend of simultaneous change with the stress of the specimen; the appearance of the maximum ringing count of the cylindrical assembly is earlier than the appearance of the maximum stress value, while the maximum ringing count of the cubic assembly lags the appearance of the maximum stress value.

       

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