Hydroelastic Dynamics Calculations Of Very Large Floating Structures Under Wave Action

In recent years,due to the progress and development of human society,the demand for land space and resources is increasing day by day.Therefore,there is an urgent need to research and develop Marine energy and space resources as soon as possible to alleviate this problem.The 14 th Five-Year Plan points out that China should focus on the fields of Marine resources,Marine engineering and Marine environment to study and make breakthroughs in a large number of core key technologies,so very large floating structure(VLFS)have a very broad application prospect.VLFS is a kind of ocean structure with large horizontal scale.Under the action of flow field,rigid body motion and structural deformation will occur.Therefore,hydroelastic dynamics analysis must be carried out by coupling the two to solve the problem of first-rate solid coupling.In this paper,based on potential flow theory,the hydroelastic response of a very large floating body is calculated by using Green's function method.In this paper,a typical box-type VLFS is simplified into an elastic thin plate by using the Kirchhoff-Love thin plate theory,and the motion equation of the floating body structure is obtained by using the vibration differential equation of the thin plate.By dividing the floating body into elements,the velocity potential of each element is solved by Green's function method,and then the overall distribution of incident velocity potential,diffracted velocity potential and radiation velocity potential is obtained.The fluid velocity potential was substituted into the fluid-solid coupling motion equation to obtain the modal amplitudes,and the modal superposition method was used to calculate the structural displacements.Finally,the hydroelastodynamics response of the very large floating body was obtained.In this paper,the mathematical software Mathematica is used to write a calculation program,and the feasibility of the numerical method and the applicability of the program are verified by calculating and comparing the numerical examples in literature.The influence of ocean working conditions and changes in physical properties of structures on the hydroelastic response of floating body structures is further explored.The main contents and research conclusions are as follows:(1)To be precise in different sea conditions are analyzed and compared the hydroelastic response of the wavelength of the waves,wave direction Angle is discussed,the influence of wave height and the change of water depth to be precise,including floating body structure of a typical location change of stress state,and Von Mises stress and the maximum stress value varies with the wavelength,wave direction Angle,and the changes of wave height and depth of the water The hydroelastic response law of the very large floating body is analyzed,the ultimate stress value of the floating body structure is obtained,and the dangerous sea state is predicted.(2)Explore the physical properties of the typical sea condition be precise structure change influence on hydroelastic dynamic response,analyzes the different length,thickness and material of the floating body structure hydroelastic response,the results include different thickness be precise relation between the displacement and the maximum stress value,and the maximum stress value and the maximum stress under different length value distribution,The elastic deformation and Von Mises stress distribution of the structure with different materials were compared.The calculation results and research conclusions of VLFS have certain reference significance for the design and construction of VLFS in the future.