The Study Of Ship With Nonlinear Rolling In Waves

The nonlinear rolling of ship in waves is one of the important reasons for the ships capsizing. Focused on this phenomenon, the nonlinear dynamics method is used on the theoretical study of ship stability in this paper, and its application on one fishing boat was tried out. The article is divided into five chapters.The first chapter, summarizes the research situation of the ship's stability, and discusses the research method of nonlinear rolling. The second chapter briefly introduces the method of nonlinear dynamics and describes the main ideas of multiple scales method and solving steps in detail. Chapter 3 shows the mathematical model firstly, and then gives the mathematical model of this paper. More details on hydrodynamic coefficients and solving problems. Via complicated derivation, the fourth chapter obtains the approximate analytical solution of nonlinear roll equation on beam waves. After computer realization, the program is applied on one fishing boat. Chapter 5, through the analysis on model test and theoretical forecasting results from WASIM discuss the feasibility of theory calculation in this thesis.In conclusion, using nonlinear dynamic method, this thesis studies the nonlinear roll motion equation and observed the resonance steady-state responses of analytical solution; forecast the roll movements of ship in beam waves through the simulation calculations on different wave conditions of ship's nonlinear rolling motion. Furthermore, the results are compared with experimental and the WASIM results aiming to verify the feasibility of theory calculation in this thesis and reveal some nonlinear characteristics on ship's rolling motion.