单轴压缩煤岩变形破裂电磁辐射与应力耦合规律的研究

利用实验研究、理论分析和数值模拟相结合的方法，研究了单轴压缩条件下煤岩变形破裂过程中产生的电磁辐射(EME)强度与煤岩内部应力之间的耦合规律。在煤岩材料损伤特性和强度统计理论的基础上，研究了受载煤岩变形破裂的三维力．电耦合本构关系，从理论上分析了煤岩变形破裂过程中电磁辐射强度和脉冲数与加载应力之间的关系，认为它们之间的关系可以用多项式来表征。煤岩变形破裂过程中的力-电耦合计算结果表明：EME先是逐渐增加，达到一个峰值后快速降低，这与实验测定结果的趋势是一致的：加载速度越大，EME信号也越强：随着煤岩样品强度的增加，EME也是逐渐增大的，其中强度最高的砂岩产生的EME强度也最大，以下依次是泥岩、硬煤和中硬煤。这些都说明采用的模型和计算方法是合理的，可以有效地模拟煤岩单轴压缩过程电磁辐射信号的变化规律。

RESEARCH ON COUPLING LAWS BETWEEN EME AND STRESS FIELDS DURING DEFORMATION AND FRACTURE OF COAL AND ROCK IN UNIAXIAL COMPRESSION

Based on the laboratory experiment,theoretical analysis and numerical simulation,the coupling laws between electromagnetic emission (EME) intensity and stress fields during the deformation and fracture of coal and rock in uniaxial compression are researched in this paper. On the basis of damage characteristics and statistical strength theory of the brittle material like coal and rock,the three dimensional coupling relationship between EME intensity and stress is researched. The relations among the EME intensity,pulse numbers and stress are analyzed theoretically. The theoretical analysis shows that the coupling relationship can be expressed by multinomial approximately. The testing results show that the EME signal increases with stress approximately with the relation of cubic multinomial,the signal of EME emitted in the course of deformation and fracture of coal or rock in compression is relevant to the stress basically,and the intensity and pulse of EME increase with the stress, deformation and fracture. The results of coupling calculation show that the EME signal first increases to a summit value,then decreases suddenly,and it increases also with loading rate and strength of coal and rock,which is consistent with the experimental results.