Modeling of vibration response of rock by harmonic impact

• Physical and mathematical models of micro vibration are presented.
• The amplitude-frequency characteristic curve of rock is investigated.
• Numerical simulation and indoor experiment are conducted to analyze vibration response.
• The maximum vibration displacement is obtained when the rock is resonant.
• Harmonic impact drilling can improve the rate of penetration.

Modeling of vibration response of rock by harmonic impact is done in this study, and the results of numerical analysis and indoor experiments are presented. Also, the amplitude-frequency characteristic curve of rock in steady state response is investigated based on the principle of vibration. Three main control parameters are considered, including the density of rock, the excitation frequency and the impacting amplitude of the indenter.It is confirmed that when the excitation frequency is the same as the natural frequency of rock, the maximum vibration displacement of rock can be obtained. The vibration response of rock increases with the increase of excitation frequency and impacting amplitude, and decreases with the increase of the density of rock.The vibration characteristics of rock by harmonic impact are validated by numerical analysis and the experimental results. Harmonic vibration impact drilling can greatly enhance the vibration amplitude of rock, and further improve the rate of penetration compared with the conventional drilling.