Abstract Numerical simulations of initial dynamic extension of microcracks of mode I under shock wave loading of blasting using ABAQUS embedded with a numerical module of dummy nodes and a load subroutine of air wedge was carried out to investigate the blasting-enhanced permeability of low-permeability sandstone with uranium deposits(BEPUD) . The numerical results indicated that the longer duration of rise time of shock waves,the more microcracks were activated in rocks. High peak pressure of shock wave led to high release rate of dynamic energy at crack tips. The excessive or insufficient peak pressures of shock wave were not conducive for the initial dynamic extension of microcracks and fully consumption of explosive energy. In virtue of the comparison of results from the static and the dynamic numerical analysis under explosive gas load,more crack growth in the dynamic analysis was found than in quasi-static analysis. The dynamic analysis explained better the phenomenon of the movement of crack instability.
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Received: 16 September 2013
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