潜孔钻头端面切削齿载荷仿真研究

A Simulation Study on the Cutter Loads on the End Face of DTH Bits

为使潜孔钻头布齿更加合理及为钻头结构改进提供理论依据,达到提高潜孔钻头破岩效率、延长其使用寿命的目的,需要了解潜孔钻头端面切削齿的载荷分布。为此,建立了平面、凸面和凹面3种端面形式的潜孔钻头三维模型,以显式动力分析软件ANSYS/LS-DYNA中常用的H-J-C模型为材料模型,并利用H-J-C模型中的等效屈服强度、压力、积累损伤等函数对潜孔钻头的破岩过程进行仿真,分析不同齿圈上切削齿的载荷状态,并将切削齿载荷分解到轴向、径向及切向3个方向,运用控制变量的方法对3种不同端面形式潜孔钻头的切削齿进行力学分析。研究结果表明:凹面潜孔钻头的轴向载荷峰值最大且径向载荷峰值最小;潜孔钻头切削齿载荷的主要差别在边齿及其相邻齿圈的切削齿上,与其余齿圈上的切削齿关系不大;潜孔钻头边齿的载荷最大,易损坏。模拟结果可为切削齿的选择、切削齿的分布及潜孔钻头的结构设计提供依据。

In order to make the DTH bit tooth arrangement more reasonable and to provide a theoretical basis for the improvement of bit structure, so as to improve the rock breaking efficiency of the DTH bit and to prolong its service life, it is necessary to understand the load distribution on the end face of DTH bit. Therefore, a three-dimensional model for DTH bits has been established, with three kinds of end faces, including plane, convex face and concave face, which taken the H-J-C of explicit dynamic analysis software ANSYS/LS-DYNA as the material model, and used the equivalent yield strength, pressure and accumulated damage of H-J-C to simulate the rock breaking process of DTH bits. The load status of cutting teeth on different tooth rings has been analyzed, and they decomposed the loads into three directions： i. e. axial, radial and tangential. At the same time, the mechanical analysis for cutting teeth of the DTH bit with three kinds of end faces were conducted by controlling variables. Research results showed that DTH bits with concave surfaces had maximum axial loads and minimum radial loads; the main differences of loads on cutting teeth of DTH bits were reflected predominantly by side teeth and neighboring teeth, it has little relation with the cutting teeth on the other rings. With maximum loads, side teeth on DTH bits are susceptible to damage. Simulation results may provide reliable guidance for selecting and arranging the cutting teeth, and for designing the structure of DTH bits.