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牙轮钻头的纵向振动对钻井过程的影响很大，也是造成钻柱振动的直接原因。在3点假设和简化条件下，利用钻柱动力学有限元模型的数值计算方法，建立了钻柱振动的有限元模型；在考虑钻头一岩石互作用力学模型的基础上，建立了钻头纵向振动动力学仿真模型，共叙述了具体的仿真过程。通过仿真计算可以预测钻头的动钻压及进尺。对81/2XHP2S钻头的仿真结果表明，钻头的动钻压可以达到钻压的2倍以上，较好地反映了钻头的动力学特性。
Longitudinal vibration of roller cone bit has a great influence on the drilling process and is also the direct cause of drill string vibration. Based on the three-point assumption and simplified condition, the finite element model of the drill string vibration was established by using the numerical calculation method of the dynamic finite element model of the drill string. Based on the rock-rock interaction mechanics model, the longitudinal vibration of the drill bit Dynamic simulation model, a total of described the specific simulation process. Through the simulation calculation can predict drill bit drilling pressure and footage. The simulation results of the 81 / 2XHP2S drill show that the bit drilling pressure can reach more than twice the weight-on-bit, which reflects the dynamic characteristics of the drill bit well.