Fatigue Strength Analysis Of SHIP

The military is inseparable from the development of the navy.With the development of the shipbuilding industry,the application of new materials,as well as the popularity of high-strength steel,the structural strength of ships has greatly increased.Fatigue damage has become one of the main modes of ship structural failure,which attracts attention of many scholars both here and abroad.This paper is mainly about fatigue assessment of the tank segment based on Simplified analysis method and the Spectral analysis method.The research results provide a powerful analysis basis for the optimal design of the ship.In this paper,the motion response,hydrodynamic pressure distribution and vertical bending moment of cross-section of the ship under regular wave in arbitrary direction are calculated based on three-dimensional potential flow theory.Then the data is used in the fatigue assessment of tank segment,and provides the basis for hydrodynamic analysis,which accelerates the hydrodynamic research process of the ship structure.In order to ensure that the ship has sufficient safety margin during navigation,the structural fatigue strength of the device must be evaluated at the initial stage of design.This paper uses Simplified analysis method at first to evaluate the fatigue failure.Later it uses the Spectral analysis method to have direct calculation.The finite element software PARAN was used to establish the local finite element model of the three-cabin ship structure,this paper chooses full-load cruising state to simulate the working status of the ship and adds hydrodynamic data into the model to calculate fatigue stress and get the deformation results.At last,this paper has a comparison between the Simplified analysis method and the Spectral analysis method.