Dynamic Analysis of BTA Deep-Hole Drilling Shaft System

Abstract

Abstract. Numerical investigation was conducted into dynamics of deep-hole drilling shaft system. The rotating drilling shaft was modeled as a Rayleigh beam conveying the fluid and subjected to torque, compressive axial force and support constraints. From the viewpoint of rotor dynamics and fluid-structure interaction, the governing equation of the drilling shaft system for lateral vibration was obtained taking into account of the fluid-structure interaction, the rotational inertia, the gyroscopic effect, the effect of the motion constraints and frictional damping generated by the surrounding fluid. The influence of the cutting fluid flow velocity, rotational angular velocity, torque, compressive axial force, and the support constraints on natural frequency and stability of the drilling shaft system was examined. It has been found that the cutting fluid flow velocity, compressive axial force and torque decreases natural frequencies of the drilling shaft system, whereas rotational angular velocity and support constraints can improve the stability of the drilling shaft system.