Dynamic analysis of an underwater suspension system in ocean currents with method of averaging

Abstract

Underwater suspension system is simplified into a single degree of freedom model with restoring force and quadratic damping. Nonlinear mathematical model of the suspension unit oscillating in still water and in ocean currents is established. And its analytical solutions are obtained with method of averaging. Results show that analytical solution with the method of averaging have small differences with numerical solution based on the fourth-order Runge-Kutta and can effectively describe the underwater oscillation, and solution with weaker nonlinear term has the better approximation. With large mass, short tether length and large current velocity, the analytical solution obtained with method of averaging is closer to the numerical solution.