Multi-fractal characteristics of electromagnetic radiation with loaded coal

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 ( ΔDq ) is closely related to the coal and rock stress,and the width of multi-fractal dimension ( ΔDq ) 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 ( ΔDq ) can be used for evaluating the deformation and failure of loaded coal.