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为研究煤岩动力灾害发生前兆特征,即该过程中的电磁辐射信号产生规律,应用煤岩单轴加载破坏测试系统进行原煤及型煤煤样煤岩破裂过程电磁辐射测试试验。对原始电磁辐射信号进行集合经验模分解(EEMD),并在分解各个固有模态函数(IMF)分量波形的基础上,计算各IMF分量在原始辐射信号中的能量比例,确定原始信号的主要频段及优势频段。试验结果表明,煤岩破裂过程先后经过初始压缩阶段、弹性变形阶段以及加速破裂阶段。随着压力的不断增大,电磁辐射信号随着大量裂隙的形成而产生,且电磁辐射信号的强度与压力正相关。当压力增大至使煤体发生首次错动数值时,其电磁辐射信号强度达到极值,此后错动强度不断降低,电磁辐射信号强度也逐步下降。
In order to study the precursor characteristics of coal-rock dynamic disasters, that is, the law of electromagnetic radiation signal generation in this process, the coal-rock uniaxial load failure test system was used to test the electromagnetic radiation of coal and briquette-like coal-rock fracture processes. Based on the EEMD, the energy of each IMF component in the original radiation signal is calculated and the main frequency band of the original signal is determined And the dominant band. The experimental results show that the process of coal and rock rupture passes through the initial compression stage, the elastic deformation stage and the accelerated fracture stage. With the increasing pressure, electromagnetic radiation signal with a large number of cracks generated, and the intensity of electromagnetic radiation signal is positively correlated with pressure. When the pressure is increased to the first dislocation of the coal body, the intensity of the electromagnetic radiation reaches the extreme value, and then the intensity of the electromagnetic wave declines continuously and the intensity of the electromagnetic radiation decreases gradually.