Non-Linear Dynamic Analysis of Drill String System with Fluid-Structure Interaction

In this research, the non-linear dynamics of drill string system model, considering influence fluid—structure coupling and effect support stiffness, are investigated. Using Galerkin’s method, equation motion is discretized into a second-order differential equation. On basis an improved mathematical numerical simulation carried out using Runge—Kutta integration method. The effects parameters, such as forcing frequency, perturbation amplitude, mass ratio flow velocity, on dynamic characteristics studied under different stiffness coefficients, in which bifurcation diagrams, waveforms, phase diagrams Poincaré maps provided. results indicate that there various model behaviors for parameter excitations, periodic, quasi-periodic, chaotic jump discontinuity. changes from to periodic through inverse period-doubling bifurcation, has significant response system. Through in-depth study problem, can be better understood theoretically, so provide necessary theoretical reference prevention measures reduction number drilling accidents, while facilitating optimization process, understanding rich complex nonlinear deep-hole further vibration