基于ANSYS的钻柱扭振模态分析

An ANSYS-based torsional vibration modal analysis of drill string

应用ANSYS软件建立了钻柱的扭转振动有限元模型。经过合理的假设,通过模态分析技术计算分析得出了钻柱扭转振动规律。分析结果表明,钻柱扭转振动的固有频率随着钻柱长度的增加而显著减小;通过采用合理的钻机转速,可以避开临界转速,避免引起共振;钻柱扭转振动最大角位移位置因主振型的阶数不同而变化。该项研究结果对于常规的回转钻进中采用合理的减振措施等方面具有现实的指导意义。

The ANSYS software was applied to establish thetorsional vibration finite element model of drill string. Thetorsional vibration law of drill string was obtained by using therational hypothesis and the modal analysis technology. Theanalysis shows that the inherent frequency of the drill stringtorsional vibration decreases remarkably with the increase ofthe string length. Adoption of reasonable rotational speed ofdrilling rig can avoid critical rotational speed and occurrence ofresonance. The maximum angle displacement position of thecone torsional vibration changes with the orders of the mainvibration mode. The research can serve as a practical guide toadoption of rational vibration reduction measures in rotarydrilling.