Research Of Structural Characteristics On A New Kind Submerged Pressure Hull And Ship Hull Composed By Composite Material

The composite material has playing a vital role in aeronautical structure since its superior advantages including high specific strength and stiffness. With the continuous innovation of composite and increasing demands of new kinds of marine structure, the composite marine structure was paid more attention. In this paper, the structure characteristics of a new kind of submerged hull and ship hull composed by composite material is studied.Firstly a comparison between isotropic polyhedrally cylindrical shell and cylindrical shell ring stiffened cylindrical shell is conducted based on the theoretical analysis and numerical simulation calculations, the results show that polyhedrally cylindrical shell has advantage at buckling resistance ability. However imperfection like stress concentration and low axial stiffness accompanied with it will limit the usage when subjected to hydrostatic pressure. To reduce affections of these imperfections some kind of improvement structure is tested and compared with original ones.Then take advantage of the superiority of composite material, six composite polyhedrally cylindrical shells are designed and manufactured to conduct axial compression tests. The composite polyhedrally cylindrical shell will fail at the same position as isotropic polyhedrally cylindrical shell which means that they share same characteristics in some aspects. Simulation results of the test process are in good agreement with experimental results. Further several kinds of composite laminates have been used for polyhedrally cylindrical shell to analyses the influence of different ply schemes. The results shows using better materials in top and bottom layers can improve buckling resistance ability of polyhedrally cylindrical shell and the foam core sandwich material has same effect.Finally, on the basis of the simulation method and relevant classification rules this paper propose algorithms about overall strength of big composite ship and wave impact strength of small high speed composite vessel.