高级检索

煤体破坏裂纹盒维数与其磁信号关联特征研究

Correlated characteristics of crack box dimension and magnetic signals during coal failure

  • 摘要: 裂纹为煤体受载破坏发生发展的重要表现,而磁信号做为煤体受载破坏能量外泄途径之一,两者之间必然存在相关关系。为研究煤体破坏裂纹与其产生磁信号间量化关系,进一步完善动力灾害磁信号监测预警技术相关理论,首先借助RFPA2D数值模拟软件模拟不同层理性质及数量煤体静载破坏下裂纹形态特征,对比室内试验结果证实了数值模拟结果的可靠性,其次结合所建力-磁耦合模型,得到不同试样破坏后磁脉冲数量及释放磁能量,分析层理性质、数量与磁脉冲数、磁能之间关联特征,再次利用Matlab软件对模拟所得破坏后含裂纹试样进行预处理并分别计算试样裂纹盒维数,分析裂纹盒维数与层理性质及数量的关联特征,最后综合分析试样静载破坏后裂纹盒维数与磁脉冲数、磁能之间关联特征。结果表明:不含层理试样破坏后裂纹盒维数最低,含水平层理试样,裂纹盒维数与层理数量呈线性正相关关系,含垂直层理试样,裂纹盒维数与层理数量之间无显著相关关系。含水平层理试样,层理数量与磁脉冲及磁能呈正相关关系,对于含垂直层理试样,层理数量与磁能呈负相关关系,与磁脉冲数关系不显著。含水平层理试样,裂纹盒维数均与总磁脉冲数、总磁能呈现出很好的正线性相关关系,而含垂直层理试样,裂纹盒维数与总磁脉冲数呈现较好的负线性相关关系,与总磁能之间不存在相关关系。

     

    Abstract: Crack is an important manifestation of the occurrence and development of coal failure under load, and magnetic signal is one of the ways of energy leakage of coal under load, and there must be a correlation between the two. In order to study the quantitative relationship between cracks and magnetic signals generated during the destruction of coal, and to further improve the theory of the monitoring and early warning technology of dynamic disasters used by magnetic signal in coal mine, firstly, RFPA2D numerical simulation software was used to simulate the crack morphology characteristics with different bedding properties and quantities of coal under static load. The reliability of the numerical simulation results was confirmed by comparing the experimental results in the laboratory. Secondly, combined with the established force-magnetic coupling model, the number of magnetic pulses and energy released after the failure of different samples were obtained. The relationship among bedding properties and magnetic pulse, magnetic energy, and the relationship among bedding quantity and magnetic pulse, magnetic energy were analyzed. Thirdly, the MATLAB software was used again to preprocess the cracked samples obtained from the simulation and calculate the crack box dimensions of the samples respectively. The correlation characteristics between the crack box dimension and the bedding properties and quantity were analyzed. Finally, the correlation characteristics between the crack box dimension and the number of magnetic pulses and magnetic energy after static load failure of the sample were comprehensively analyzed. The results show that the crack box dimension of sample without the bedding is the lowest, and for samples with horizontal bedding, the crack box dimension is linearly correlated with the number of bedding. There is no significant correlation between the crack box dimension and the bedding quantity for the sample with vertical bedding. For samples with horizontal bedding, the number of bedding has a positive relationship with magnetic pulses and magnetic energy. For samples with vertical bedding, the number of bedding has a negative relationship with magnetic energy, but not significantly related to the number of magnetic pulses. For the samples with horizontal bedding, the crack box dimension has a good positive linear correlation with the total number of magnetic pulses and total magnetic energy, while for the samples with vertical bedding, the crack box dimension has a good negative linear correlation with the total magnetic pulse number, but there is no correlation with the total magnetic energy.

     

/

返回文章
返回