Study On Mechanical Properties Of Marine Composite Sandwich Structure

With the development of new material and technique in ship, composite sandwich structure had been widely accepted because of excellent characteristics which was high strength and stiffness, low weight and durability. As a result, the study of mechanical properties of the composite sandwich plate played a important role in its research and application. So it's necessary for us to study.Marine sandwich plate for statics and dynamics problems of composite laminated structure were analyzed by theory and numerical simulation based on the laminated plate theory and feature of sandwichstucture. Composite sandwich structure mechanics model was established and solved by the MATLAB programming to analyze the mechnical characteristics of sandwich structure bending and the parameter influence, free vibration and dynamic response. The impact resistance of marine composite sandwich plate under the action of shock was studied based on the finite element software. Appling composite sandwich plate structure to hull grillage beam, and statics problem has been carried on the simulation analysis. In this paper, conclusion are good for the application of new type of composite structure in the hull and the optimization design. Specific work were mainly included as follows.(1) First, the basic theories of composite sandwich plate were introduced, incuding Reissner sandwich plate theory and Hoff sandwich plate theory, and they were directly applied to composite sandwich plate. According to the mechanical properties of composite sandwich plate, first-order Zig-zag deformation theorietical model based on Sriniva Zig-zag model was proposed which considerated shear effect face of sheet. The government equations of the two kinds of soft and hard sandwich model based on first-order Zig-zag were presented. In order to improve the plate of the in-plane displacement, high-order Zig-zag theory model was proposed, and the emotion equations were derived according to the Hamilton principle.(2) According to several kinds of sandwich plate model(Reissner theory, Hoff theory, the first-order Zig-zag deformation theory, higher order Zig-zag shear deformation theory), the government equations were derived to calculate bending problem of composite sandwich plate. Then the accuracy of several kinds of theoretical calculations for the problem of statics through comparing with the results of other papers were verified. Then the influence of parameters(surface core thickness ratio, aspect ratio and modulus ratio) on the properties of sandwich plate bending was studied, and the validity of the model of composite sandwich plate of the finite element software ANSYS was verified.(3) According to the motion equation of composite sandwich plate, the problem of free vibration of composite sandwhich plate was solved, and compared with finite element software ANSYS and the results of other papers. Then the problem of free vibration and study the influence of parameters was solved. Then the numerical algorithm was used to study lateral dynamic response at the elastic deformation stage of composite sandwich plate. Then the influence of damping ratio and core layer thickness parameters on the vibration characteristics of sandwich structure was studed. The action of the destruction of the composite sandwich plate and energy absorption under object impact based on LS-DYNA.(4) The static analysis of hull structure with composite sandwhich was studed, which contributed to further study of application on the ship. The influence of parameters on the properties of sandwich plate bending was studied...