Current waveform characteristics and rock-breaking effect of metal wire explosion
To investigate the current waveform characteristics and rock-breaking effects of metal wire explosions(MWEs)under different voltages,the paper conducts experimental research on metal wires in both air and red sandstone media using a high-voltage pulse discharge system.Through the comparison of the differences and similarities in current waveforms of metal wires at different voltages in both air and rock,it establishes a relationship between the peak current of metal wires and voltage.Furthermore,in combination with experimental observations of the fragmentation of red sandstone induced by MWEs,it further analyzes the patterns of crack propagation and fragment distribution in red sandstone under the influence of different high-voltage pulse loads.The experimental results demonstrate that the peak current of MWEs in both air and rock exhibit a linear relationship with discharge voltage,however,under the constraints of the rock medium,both the peak current and oscillation duration in rock are smaller than those in air.The shock wave generated by MWEs in rock induces radial motion of rock pore wall particles,which resultes in tangential tensile stress and leads to a crack propagation pattern primarily characterized by radial cracks originating from the metal wire center.It is also found that the discharge voltage has a significant impact on rock fragmentation.As the discharge voltage increases from 40 kV to 80 kV,the number of primary cracks increases from one to multiple,which gives rise to a pronounced increase in rock fragmentation and a more concentrated distribution of fragment sizes.These experimental findings provide valuable references for the application of high-voltage pulse discharge technology in breaking solid materials like rocks.
metal wire explosiondischarge voltagecurrent waveformrock fragmentred sandstone
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