【摘要】 潜孔锤钻头冲击钻进的过程是一个高度非线性、大变形、破坏的过程。对这一复杂过程,目前主要是利用实验方法来进行研究,致使钻头设备的开发与研制一直处于传统的经验或实验模式下进行,设计与制造周期长、成本高,产品严重老化、缺乏市场竞争力。应用非线性显式三维有限元求解程序LS-DYNA3D,采用与岩石性质较接近的混凝土模型,对钻头硬质合金球齿冲击混凝土板的过程进行仿真计算,讨论不同球齿冲击速度下混凝土的变形及破碎机理,分析球齿的冲击力、侵入混凝土的速度、位移及冲击力-凿入深度曲线等,为研究钻头与脆性材料的作用过程及钻头的优化设计提供一种有效的分析方法。更多还原

【Abstract】 The process of Down-the-Hole(DTH) hammer drilling is very complex for its high non-linear,large deformation and damage behavior.For this complex problem,currently studies are mainly based on experiments.Taken brittle material concrete as the impact specimen,this work employs the explicit time integration nonlinear finite element code LS-DYNA to analyze the impact process of DTH hammer bit insert.The impact forces,insert penetration velocity and force-penetration behavior of concrete under bit insert impact has been recorded,with the formation of concrete craters and fractures has been also investigated.According to the simulated results,it is believed that the numerical simulation method will contribute to an improved knowledge of concrete fragmentation under bit insert impact,which will in turn help to enhance drilling efficiency through the improved design of bit tools and equipment.更多还原