Effect of Static Loading on Rock Fragmentation Efficiency Under Ultrasonic Vibration

In this study, the effect of static loading on the rock fragmentation efficiency of ultrasonic vibration drilling was investigated by numerical simulation combined with experimental verification. The inner stress and strain of rock under different vibration frequencies were analyzed, and a static loading–inherent frequency relationship curve was obtained. The inherent frequency increased logarithmically with the magnitude of static loading. The resonance state may be broken with increasing static loading, affecting the drilling efficiency. To improve the rock fragmentation efficiency in the process of ultrasonic vibration drilling, the key point is keeping the inherent frequency of rock always similar to the vibration frequency.