Hydroelastic Variational Principles Of Very Large Floating Structures And Their Application

With the continuous development of economics in the world,the resources on the mainland have been almost exhausted.Therefore,people devote their efforts to explore the ocean resources.How to use marine resources efficiently has become a hot topic.Very Large Floating Structure(VLFS)is one of the most main platforms for people to explore marine resources in the ocean.As a result,it is necessary to speed up the research process on the structural properties and design theory of very large floating structures.The large floating structure acts as a flat and flexible ocean floating structure.Solid-liquid coupling arises as the interaction between the large floating structure and the fluid,which is inconsistent with the methods used in the analysis of traditional marine floating structures and should be solved with hydroelastic theory.The variational principle can be used for the study of problems in elastic mechanics,which has the advantage in expressing a complex physical phenomenon through a simple formula with expressing the relationship of unknown variables.This paper studies on the hydroelastic variational principles and the flexural behaviors of very large floating structures.In this paper,the basic equations and boundary conditions of hydroelasticity of floating structures are firstly classified.Then using variational integral method principle to establish the variational principles of coupling of floating structures with unbounded fluids,coupling of floating structures with bounded fluids and coupled vibration equation of floating structure with unbounded liquid.The validity of the variational priciples are verified by deriving their respective stationary values.Based on the established variational principles,the hydrodynamic response of very large floating structure can be predicted by using the plate Green's function method.It is found that the deflection decreases with the increase of the length of floating structure,while increases with the increase of the width of floating structure.