Abstract
Percussive drilling is suitable for the fragmentation of rocks and other similar materials with hard and brittle properties. Research on energy transfer efficiency is of great significance to improving the rock-breaking efficiency of percussive drilling. This paper numerically studied energy transfer efficiency and rock damage in percussive drilling with a multiple-button bit. In this study, the finite element method was used, and the concrete was selected as the research object. Moreover, the damage-plasticity model for concrete and the explicit dynamics solver in abaqus were adopted. Based on the above model, we analyzed the effects of different parameters on the energy transfer efficiency and the concrete damage. Results show that the degree of concrete damage is positively correlated with the output energy, referring to the energy actually absorbed by the concrete, of the percussive system. Under the condition of the same input energy, the energy transfer efficiency decreases as the number of buttons increases. With the increase of impact velocity of the impact hammer, the energy transfer efficiency augments. Multiple repeated impacts will cause the repeated damaging of the concrete, which reduces the energy transfer efficiency.