Dynamic Analysis of Percussion Drilling System under Harmonic Impact

As a new efficient rock‐breaking technology, harmonic impact drilling technology has received great attention, but the research on its rock‐breaking mechanism is insufficient, which limits its development. Based on the theory of vibration, a simplified model of high‐frequency harmonic vibration impact system is established in this paper. The numerical model was solved by Matlab and the motion equations of drill bit and rock at different stages of motion are obtained, respectively. Based on the factor analysis of the mathematical model, the dynamic characteristics of the impact system under harmonic excitation are studied. Finally, numerical simulations are carried out to further analyze the drilling effect of harmonic impact drilling and verify the correctness of the simplified model. The results show that when the excitation frequency equals the resonance frequency of rock, the vibration displacement of rock reaches the peak value. The drilling speed is greatly increased by harmonic impact drilling compared with conventional drilling.