In the context of rock fragmentation, the application of high voltage electric pulses results in the transfer of electrical energy onto the surface of the rock material, leading to a rapid electrical breakdown and the formation of a plasma channel. The ionized plasma expands at a fast velocity, generating a shock wave that causes significant damage to the rock’s integrity. In this study, we develope a numerical model that couples electrical, thermal, and mechanical forces to simulate the formation of plasma channels within rocks due to high-voltage electric pulses. The model’s accuracy is verified through field tests, and the results indicate that the configuration of the high-voltage pulse waveform, electrode spacing, and conductor particles within the rock impact the pathway of plasma channel formation. Prior to the formation of the plasma channel, minimal changes are observed in temperature and stress levels, with the majority of electric pulse energy dedicated to the creation of the plasma channel. Following the establishment of the plasma channel, the application of the electric pulse continues, resulting in notable alterations in temperature and stress levels. When the duration of the action reaches 10⁵ ns, the temperature and stress levels surpass 10⁴ K and 50 MPa, respectively, leading to fracture and extensive damage to the rock. The outcomes derived from the numerical model’s calculations can help to facilitate the cross-integration between physics and civil engineering and contribute to a deeper understanding of the rock fragmentation process under high voltage electric pulses.

Our research proposes a unique coupled electro-thermal-mechanical model that takes electric breakdown and heterogeneity into account to show the mechanism of rock fracturing under high-voltage electropulses. Using finite element numerical software, the process of high voltage electrical pulse injection into the rock interior for breakdown is described, and the formation law of plasma channels during the electrical breakdown process is comprehensively analyzed in conjunction with the conductor particles present within the rock. On the basis of electrical, thermal, and mechanical theories, a coupled multi-physical field numerical model of rock failure under the action of high-voltage electrical pulses is developed, and a random distribution model is utilized to simulate the potential occurrence of conductor particles in the rock. Innovative numerical model indicates plasma channel creation in the rock-crushing process. Prior to the formation of the plasma channel, the temperature and stress are approximately 10³ k and 10⁻² MPa, respectively. Once the plasma channel is formed, the temperature and stress increase abruptly in a short time, with the temperature reaching 10⁴ k and the stress reaching 10³ MPa or higher. In addition, it is revealed that the breakdown field strength is the essential factor in plasma channel creation. The heterogeneity of the particles within the rock and the fluctuation in electrode settings are also significant variables influencing the creation of channels. The presented model contributes to a better understanding of the mechanism of rock fragmentation during high-voltage electrical pulses, which has substantial implications for oil exploration and mineral extraction.