Study on Energy Dissipation and Fractal Characteristics of Fractured Sandstone Under Impact Load
SHPB dynamic test bed was used to carry out impact tests on red sandstone samples with different fracture dips,recording the mass-particle size distribution after rock fragmentation and calculating its fractal dimension,to analyze the fractal characteristics of rock crushing and the law of energy consumption under impact load.The results show that:Under the same impact load,the dynamic compressive strength increases and the strain rate decreases with the increase of the crack dip angle,and the dynamic compressive strength increases most obviously when the dip Angle increases from 45° to 60°;The existence of prefabricated cracks in rock samples will hinder the transfer of stress waves,leading to the increase of reflection energy and the decrease of transmission energy.Moreover,with the increase of inclination Angle,the influence of prefabricated cracks will be gradually weakened,while the reflection energy and transmission energy will be continuously reduced and the dissipated energy will be almost not affected by the inclination Angle of cracks;The fractal dimension of fractured rock mass increases linearly with the increase of fracture dip angle and dynamic compressive strength and decreases with the increase of strain rate.The relationship between fractal dimension and rock-crushing dissipation energy satisfies the power function.