基于流固耦合钻柱系统动力学模拟

通过研究钻柱系统的非线性动力学问题，建立了钻柱系统流固耦合动力学方程.利用Galerkin截断方法，将偏微分方程转化为常微分方程，采用Runge-Kutta积分法进行了数值模拟，研究了不同支撑刚度系数下，系统脉动频率、脉动幅值和质量比等参数激励对钻柱系统动力学特性的影响.结果表明，在不同的参数激励下模型表现出丰富的动力学行为，呈现不同的周期运动、拟周期运动、混沌运动和跳跃间断现象.系统由混沌运动通往周期运动的路径为倍周期倒分岔形式;支撑刚度在一定程度上引起系统固有特性的改变，对系统的非线性动力学行为有复杂的影响.

Dynamic Simulation of Drilling String System Based on Fluid-Structure Coupling

The nonlinear dynamics of the drilling string system is studied， and the fluid-structure coupling dynamic equation of the drilling string system is established. With the Galerkin truncation method， a set of partial differential equations are diverted into ordinary differential equations. Numerical simulation is carried out by using the Runge-Kutta integration method and the effects of parameters such as pulsating frequency， pulsation amplitude and mass ratio on the dynamic characteristics of the drilling string system are investigated. The results show that there are various dynamic behaviors for the model in different parametric excitation such as periodic motion， quasi-periodic motion， chaotic motion and jump discontinuous phenomenon. Besides， the path from chaotic motion to periodic motion is in the form of period-doubling inverse bifurcation， and the support stiffness can cause a certain change in the inherent characteristics of the system， which has a complex impact on the nonlinear dynamic behavior of the system.