Optimum design of composite wing structures by a refined optimality criterion

Abstract

Techniques for the optimization of composite with structures are investigated. The refined optimality criterion technique presented in this paper is an algorithm combining a criterion based on the Kuhn-Tucker conditions and the technique of fully stressed design. The main advantages of this method are the generality of use, the efficiency in computation, and the capability of identifying automatically the set of critical constraints. Sensitivity analysis of constraints is based on the virtual load principle. This method is especially suitable for optimum design of large-scale structures. A modular type computer program, ARS 5 (Automatic Resizing System 5), is developed in accordance with the finite element method, refined optimality criterion, sensitivity analysis and Fortran-77 language for the optimization of composite wing structures subjected to sizes, stresses, displacements, twist and buckling constratints. Numerical results for a triple-spars composite wing structure reveal that the present technique is quite efficient and reliable.