基于LS-DYNA的大容腔潜孔锤钻头结构研究

Research on Large Cavity Structure of DTH Hammer Bit Based on LS-DYNA

摘要:

提出通过大容腔结构改善潜孔锤钻头与冲锤质量比来提高液动潜孔锤钻进效率的方法，并应用LS-DYNA显示动力学分析手段，对常规潜孔锤钻头和新型大容腔结构潜孔锤钻头的碎岩效果及应力状态进行仿真分析，结果表明：采用大容腔结构减小潜孔锤钻头的质量，调整钻头与冲锤质量比，可明显提升碎岩效果；冲锤与钻头质量比由0.79变化到0.91，岩石碰撞过程中吸收的最大冲击能变化率以及碰撞结束后的最终吸能变化率分别为41.13%和67.17%；两种大容腔潜孔锤钻头的受力均满足长期作业的疲劳强度要求，数值模拟计算结果表明，该钻头结构在施工中具备可行性。

Abstract:

A method of improving the mass ratio of DTH hammer and impact hammer by large cavity structure is presented to increase the drilling efficiency of DTH hammer, and LS-DYNA dynamic analysis method is applied to conduct the simulation analysis on the large cavity structure of DTH hammer bit’s rock fragmentation efficiency and stress state. The results show that the large cavity structure can reduce the mass of DTH hammer bit and adjust the mass ratio of DTH hammer bit and the impact hammer, which can obviously improve rock fragmentation efficiency. The mass ratio is changed from 0.79 to 0.91, the biggest absorptive impact energy change rate in the processes of rock collision and after the collision were 41.13% and 67.17% respectively. The forces of two kinds of large cavity DTH hammer bits meet the fatigue strength requirements for long-term operation. The numerical simulation calculation results show that this structure of DTH hammer bit is feasible in the construction.