Cyclic shock damage characteristics of electrohydraulic discharge shockwaves

Abstract

To improve the quality of electrohydraulic discharge (EHD) shockwaves cracking effect and reduce its damage, the study examines the cumulative damage characteristics of rock induced by shockwaves generated by EHD. Voltage, current, energy, efficiency, wave velocity, and peak value of incident and transmission shockwave of a liquid–solid interface at different discharge energies are given based on the observation of the shockwaves of established discharge platform. The cyclic impact cracking test is conducted on cement samples. The cement samples are effectively cracked, and the surface formed several cracks. The tests results indicate that the cumulative effects of different cyclic loading modes exist under the action of EHD shockwaves. An upper limit exists on the cumulative effect, and the breakdown voltage affects the maximum effective number of discharges and affects the depth of action. Particle flow code 2D (PFC2D) simulation is used to simulate the cement samples under the same experimental conditions. The development process and shape distribution of the internal microcracks under different loading ene