Experimental research on dynamic mechanical characteristics of layered composite coal-rock

Using the Separate Hopkinson Pressure Bar test device, a series of dynamic impact tests were carried out on single coal and white sandstone near incident bar. When stress wave propagates in complex with different impedance matching effects, its mechanical properties change, energy dissipation law damage characteristics are studied. The research results show that: (1) With increase velocity, peak DIF layered composite coal-rock linearly. At same speed, when changes from hard to soft, larger than soft hard. (2) dissipated density increases quadratic function density, body better effect has higher density. (3) fractal dimension degree fracture speed. component is mostly shear failure, crushed.