Discharge characteristics of high voltage pulses inside rocks with increasing their applied number

Abstract

By conducting experiments for granite and sandstone samples under different conditions, such as voltage amplitude and electrodes gap, the discharge characteristics of high voltage pulses inside the rocks with increasing their applied number have been investigated. In each of the experiments, a certain value for voltage amplitude and electrodes gap is set separately and then, pulses are applied on same surface of the rocks continuously. The time dependent voltage between the electrodes, the current in plasma and the transient states around the electrode tips are measured and recorded separately when each of the pulses is applied. By means of the wave forms of the voltage and the current, variation laws of the discharging time and the energy release into the plasma with increasing applied pulses number have been obtained. The relation between the number of applied pulses and the critical condition of discharge inside of the rocks has been found. Further, the relation between the number of applied pulses required to discharge and the voltage amplitude has been also analyzed. The reasons of why increasing applied pulses number has such effects on discharge characteristics of them inside the granite and sandstone samples have been found and demonstrated.

Research on the Crushing of Reinforced Concrete Two-Way Slabs by Pulse Power Discharge Technology

“…This is due to the presence of reinforcement bars within these structures, which significantly constrain the progression of cracking. Such limitations play a crucial role in affecting the structural integrity, specifically in terms of resistance to crushing and demolition [49]. However, the existing research takes the discharge energy as the change parameter and does not consider the influence of the key parameter of reinforcement dosage.…”

The fragmentation mechanism of granite in electrical breakdown process of plasma channel drilling

“…Plasma Channel Drilling (PCD) is a new method (Timoshkin et al 2004;Inoue et al 2000), which has been widely used in mining and rock excavation (Yan et al 2016), mineral decomposition (Andres et al 2001;Huang and Shi 2020) and recycling of valuable resources (Duan et al 2015), etc. PCD has the significant advantages of high drilling efficiency and low cost (Biela et al 2009;Li et al 2019;Zhang et al 2017). In conventional drilling, based on hard interaction with the rock, the bit relies on its own scraping and shearing to cause damage to rock.…”