Ship System Modeling and Simulation by Using Finite-Element Multibody System Transfer Matrix Method

The ship system is a complex hull-propulsion-shaft-power multibody system composed of at least one shaft subsystem coupling with numerous flexible bodies. To achieve rapid and precise modeling of the ship system, this paper combines the advantages of rapid modeling and efficient simulation of the Multibody System Transfer Matrix Method (MSTMM) for the shaft system with the power of the Finite Element Method (FEM) for flexible bodies. The fundamental principles of the Finite-element Multibody System Transfer Matrix Method (FMSTMM) are elaborated. The general multibody system comprising the shaft and hull is divided into subsystems using MSTMM and subsystems using FEM and modal synthesis method. The dynamic equations of each subsystem and the overall transfer equation of the entire system are derived separately. The constraint relationships at the subsystem connection points are utilized to formulate the overall transfer equation and characteristic equation of the multibody system, in order to compute of the system’s dynamic characteristics. A FMSTMM dynamic model and algorithm for the ship multibody system including shaft and hull subsystems are established. The efficient modeling and simulation of the vibrational characteristics of the shaft-hull system are achieved. The simulation and test results meet well, validating the proposed method.