The Calculation Method Of Ship Structure Elastic Wave Propagation Characteristics Based On Peridynamics Theory

Based on the vibration theory modal superposition method,finite element and other numerical analysis methods are used to analyze the dynamic response of ship structure.The dispersion phenomenon of the bending wave in the hull structure is avoided.As a result,the dynamic response analysis only focuses on the result rather than the process,and the transmission characteristics of vibration response in the structure are unknown.Vibration theory is the dynamic analysis of closed systems.While Wave theory is concerned with the vibration transmission characteristics of open systems.The propagation characteristics of elastic waves in ship structures are of great significance to guide the acoustic design of ship structures.In this paper,the propagation characteristics of structural elastic waves are studied from the perspective of wave mechanism.Establishing a mathematical model for Peridynamics calculation and analysis of elastic wave properties.The elastic wave dispersion characteristics of ship structures are studied in detail.Firstly,this paper introduces the elastic wave analysis theory based on Peridynamic method.Some basic theories and numerical solutions of Peridynamics are included.To study the theory of elastic wave propagation characteristics and deduce the formula.Proposeing the analytical method for studying the propagation characteristics of ship elastic based on Peiridynamics theory.These theories and methods are the basis of this thesis.Secondly,the wave propagation characteristics in the beam and plate model are analyzed based on Peridynamic theory.According to the propagation characteristics of longitudinal wave and bending wave in the beam structure,a specific analysis method based on Peridynamic theory was put forward,and the wave velocities of elastic wave in the beam under different frequencies were calculated by high and low frequency bands and compared with the theoretical values.Finally,the wave propagation characteristics in the simple frame model are analyzed based on Peridynamic theory.The wave propagation characteristics in two simple plate frame models are analyzed.The wave velocities of longitudinal wave and flexural wave at different positions of simple plate frame are calculated respectively.The characteristics of elastic wave propagation in two kinds of simple frame models are summarized.To lay a theoretical foundation for the analysis of elastic wave characteristics of complex ship structures.