Stiffened Composite Panel Overlay Parameters And Stability Of The Optimization Design

In this paper, an effective design optimization method for High-aspect-ratio composite wing skin is presented. Static optimization of composite laminate and buckling optimization of composite stiffened plate are taken in the process of composite structure optimization. And the buckling optimization of composite stiffened plate are composed of size optimization and stacking sequence optimization.Two steps are alternately taken in the process of composite laminate static optimization . Firstly, with fixed total strain energy criteria is used to adjust the thickness of each layer; secondly, thickness of elements iterative coefficients are derived by Kuhn-Tucker condition and full stress design method. The paper studies numerical methods of design optimization on composite stiffened plate buckling stability. Mixed penalty function , Powell algorithm , golden section method and improved coordinate rotatory method are used in the composite stiffened plate buckling size design optimization. For further improving buckling load, this paper adopts Genetic Algorithm to solve stacking sequence optimization.Finally, Delphi language is used to program the optimization procedure. As an example, the skin of composite wing structure is analyzed and optimized. The result shows that the weight and the buckling load of the skin are improved obviously. So this method has great value in the field of practical engineering.