MULTILEVEL OPTIMIZATION OF LAMINATED COMPOSITE STRUCTURES

A two-stage optimization method aiming at the optimal design of shells and plates made of laminated composites has been developed. It is bas ed on a mixture of sensitivity analysis, optimality criteria and mathe matical programming techniques. The design variables are the optimalit y criteria and mathematical programming techniques. The design variabl es are the macro-element thicknesses and the layers' angles. Weight mi nimization with material efficiency maximization are the objectives wi th constraints on stresses and displacements. Maximization of the mate rial efficiency is performed at one level using the conjugated method applied to the angles of the macro-element layers keeping the thicknes ses constant. The other level is dedicated to weight reduction using o ptimality criteria and using as variables the macro-element thicknesse s with the angles of the macro-element layers constant.