受载煤岩体电磁辐射动态多重分形特征

Multi-fractal characteristics of electromagnetic radiation with loaded coal

采用多重分形理论、物理试验相结合的方法研究了试件单轴压缩破坏过程中电磁辐射信号的多重分形谱宽度ΔD_q变化规律。研究结果表明：试件单轴压缩破坏过程中产生的电磁辐射信号具有多重分形特征;多重分形谱宽度ΔDq试件所受的应力水平有密切关系。加载初期,分形谱宽度ΔD_q着应力的增加而起伏增强;临近主破裂时,多重分形谱宽度ΔD_q到最大值0.27,进入残余变形阶段后,ΔD_q降至0.20-0.22。因此多重分形谱宽度ΔD_q动态变化与试件受载变形破裂过程具有良好的对应关系,临近主破裂时ΔD_q剧增大且达到最大临界值可以作为试件冲击破坏的判定依据,对试件冲击破坏进行提前预警。

The EME multi-fractal evolution laws during the deformation and failure processes of coal samples were studied based on fractal theory and laboratory experiment. The results show that the multi-fractal characteristic of EME series is verified. The width of multi-fractal dimension（ ΔD_q） is closely related to the coal and rock stress,and the width of multi-fractal dimension（ ΔD_q） usually increases with the increase of coal and rock stress. When coal and rock mainly rupture,it reaches a maximum 0. 27,then drops to 0. 20 - 0. 22. The characteristic parameters vary with the process of deformation and fracture of coal sample with load. The width of multi-fractal dimension（ ΔD_q） can be used for evaluating the deformation and failure of loaded coal.