基于Ls-dyna的射流式冲击器冲锤结构

基于Ls-dyna显式非线性动力学分析方法,建立"冲锤-钻头-岩石"碰撞模型,对射流式冲击器冲锤结构参数进行研究.分析等速度等质量冲锤与不同种类岩石撞击时,冲锤长度及直径变化对能量传递的影响.结合应力强度分析,探讨射流式冲击器冲锤合理结构.研究结果表明:岩石吸能值随冲锤直径减小单调提升;冲锤长度存在最优值,超过或低于最优值,岩石吸能值均减少;岩石可钻性等级或冲锤冲击末速度越高,冲锤结构改变对碎岩影响越小;最大应力始终出现在钻头尾部,相对面积小的撞击面边沿会出现应力集中,冲锤设计需兼顾钻头许用强度.

Hammer Structure of Liquid-Jet Hammer Based on Ls-dyna

A “hammer-bit-rock” impacting model was established based on the methods of the Ls-dyna explicit nonlinear kinetic simulation， and the geometrical parameters of hammer in liquid-jet hammer were studied. The effects of hammer length and diameter on energy transfer for different rocks were studied with constant mass and impact speed of hammer. The strength analysis was also made to investigate the optimal structure of a hammer. The results showed that the energy absorbed by rock increases with the decrease of the hammer diameter. When the hammer length is the optimal value， the rock can achieve the most impact energy， otherwise the energy absorbed by rock may decrease. The higher the drillability grade of rock and the impact velocity， the less the influence of hammer structure on rock breakage. The maximum stress always appears at the end of the bit and stress concentration will be found on the edge of relatively small area. The design of hammer should take the allowable strength of bit into account.