Axial-torsional coupled percussive drilling helps improve the breaking efficiency of hard rock. This paper adopted the simulation method to study the energy transfer efficiency (ETE), and rock damage in axial-torsional coupled percussive drilling with a multiple-button bit. The axial-torsional coupled percussive system model was first built in the finite element calculation platform. And then the temperature-dependent model parameter values for rock were selected. Finally, we simulated axial-torsional coupled percussive process, and analyzed the effects of various parameters. The main simulation results are as follows. In axial-torsional coupled percussive process, axial percussion has a significant influence on the ETE of torsional percussion, while torsional percussion has little influence on the ETE of axial percussion. As the impact velocity of axial percussive hammer increases, the ETE of axial percussion, the ETE of torsional percussion, and the total ETE all augment. When the impact velocity is increased from 4 m/s to 16 m/s, the total ETE is increased by 62.8%. Both the ETE of torsional percussion and the total ETE decline with the pulse torque amplitude increasing. When the pulse torque amplitude is increased from 4000 N m to 28000 N m, the total ETE is reduced by 18.3%. For convenience, we abbreviate the ratio of the torsional input energy to the total input energy as RTT. An increase in RTT, or an increase in rock temperature will reduce the ETE of axial percussion, the ETE of torsional percussion, and the total ETE. When the RTT is increased from 2.3% to 84.4%, the total ETE is reduced by 34.5%. As the axial impact velocity increases, the rock damaged areas gradually expand. With the increase of the pulse torque amplitude, the rock damaged areas sharply expand. As the RTT increases, the number of narrow tensile damaged zones extending outwardly decrease, while the connectivity between the tensile damaged areas caused by buttons augments. As the rock temperature rises, the total damaged area of rock gradually shrinks. This study provides a theoretical basis for the efficient rock breaking in axial-torsional coupled percussive drilling.

轴扭耦合冲击钻有助于提高硬岩的破碎效率。本文采用模拟方法研究了多按钮钻头轴向扭转耦合冲击钻的能量传递效率（ETE）和岩石损伤。首先在有限元计算平台中建立了轴扭耦合冲击系统模型。然后选择与岩石温度相关的模型参数值。最后，我们模拟了轴扭耦合的冲击过程，并分析了各种参数的影响。主要仿真结果如下。在轴向-扭转耦合冲击过程中，轴向冲击对扭转冲击的ETE有显着影响，而扭转冲击对轴向冲击的ETE影响很小。随着轴向敲击锤的冲击速度的增加，轴向敲击的ETE，扭转敲击的ETE和总ETE都增加。当冲击速度从4 m / s增加到16 m / s时，总ETE增加了62.8％。扭转冲击的ETE和总ETE都随着脉冲转矩幅度的增加而下降。当脉冲转矩幅度从4000 N m增加到28000 N m时，总ETE降低18.3％。为方便起见，我们将扭转输入能量与总输入能量之比简称为RTT。RTT的增加或岩石温度的增加将减少轴向冲击的ETE，扭转冲击的ETE和总ETE。当RTT从2.3％增加到84.4％时，总ETE减少了34.5％。随着轴向冲击速度的增加，岩石破坏区域逐渐扩大。随着脉冲转矩幅度的增加，岩石破坏区域急剧扩大。随着RTT的增加，向外延伸的狭窄拉伸损伤区域的数量减少，而由纽扣引起的拉伸损伤区域之间的连通性增加。随着岩石温度的升高，岩石的总破坏面积逐渐缩小。该研究为轴向-扭转耦合冲击钻削中的有效破岩提供了理论依据。岩石的总破坏面积逐渐缩小。该研究为轴向-扭转耦合冲击钻削中的有效破岩提供了理论依据。岩石的总破坏面积逐渐缩小。该研究为轴向-扭转耦合冲击钻削中的有效破岩提供了理论依据。