Layout Optimum Design Of Stiffened Panel Structure Based On Surrogate Model

Stiffened panel structure is widely used in the engineering fields of aeronautics and astronautics as they can save the structural materials, reduce the structural weight, and raise the structural efficiency. Stiffened panel structure may result in buckling or even collapse when undertaking compressive load or shear load or the both. Because of the numerous failure modes and optimum design variables, modeling, analysis and optimization are complicated. So the research of the optimum design of stiffened panel is very important.In this thesis, an optimum design method of metallic stiffened panel was built up based on surrogate model. It can be applied to the layout optimization of metallic stiffened panel structure. In this method, the initial samples were firstly created by design of experiment (DOE), secondly the responses corresponding to the initial samples, including the weight and the buckling factor, were computed by FEA, then the initial Kriging model was derived through the samples, late the samples were updated if the Kriging model was not satisified, and a new Kriging model was rederived with the updated samples. Finally the optimal solution was obtained with Trade off Method and Genetic Algorithms (GA) based on the Kriging model. Based on this method, the post -buckling optimization problem of metallic stiffened panel was also accomplished by introducing post-buckling analysis. Besides, a stacking sequence optimization method of symmetrical and balanced composite laminate was proposed in this thesis based on the above presented optimization method and bending lamination parameter. And then a two-level optimization algorithm was developed. All the examples demonstrate that they can find out the optimal solution and can verify the feasibility and validity of these methods proposed in this thesis.