The Study Of Ultimate Axial Compressive Strength And Optimum Design Of Stiffened Aluminium Panels

With the development of high-speed and light-weight ships, aluminum alloy material is finding wider and wider application in marine filed. Stiffened aluminum panel is a very important part of hull structures, which has the advantages of aluminum alloy, such as small density, high strength, anti-corrosion and good formability, and the advantage of stiffened panel bearing capacity after buckling.In recent years disastrous accidents happened in mari ne filed has drawn great attention to the traditional methods of evaluation of structural bearing capacity. The ultimate strength, namely the true strength when structure finally collapsed, of ship and its composition structures, has attracted more and more concern. Therefore it is more reasonable for structural design and safety evaluation based on the ultimate strength.The paper carried out further study on the ultimate axial compressive strength of stiffened aluminum panels, and optimization design based on the ultimate strength. The main research work was as follows:1. The generalized tangent modulus theory was applied to calculate the compressive ultimate strength of stiffened aluminum panels, and the analytical formula with associated parameters such as coordinate parameter, ultimate bending moment coefficient and the relative initial deflection were derived;2. ABAQUS finite element software was used for nonlinear finite element analysis of the stiffened aluminum panels, and the reliability of the GTMT method is further verified by finite element method;3. BP neural network corresponding to the ultimate strength of stiffened aluminum panels was established, and it was used to the influence parameters analysis, aiming at choosing the design variables which influence the ultimate strength strongly and providing guidance for optimization design.4. Optimization design to stiffened aluminum panels was based on the method of BP neural network-genetic algorithms, and MATLAB was used to the preparation and operation the optimization program. The parameters choosed before was taken as optimal parameters, the predicted output of BP neural network was used to fitness calculation, and the minimum mass of stiffened aluminum panels was searched on the premise of no ultimate strength loss, in order to make full use of the potential of aluminum material strength and structural efficiency.