Composite plate stiffness multicriteria optimization using lamination parameters

Lightweight structures are currently largely applied in several areas and their use is growing every day. In this context, composite materials are key parts to achieve design requirements due to their high potential for optimization. The lamination parameters play an important role as design variables in composite laminates layer optimization. This is due to the fact that the stiffness matrix linear with respect to them. This work aims at presenting an optimization method based upon a quadratic metamodel used to estimate the objective function. An analytical formulation to obtain the derivatives of the objective functions with respect to the lamination parameters is presented. The allowable region of the lamination parameters is also analyzed and laminate databases are applied in order to avoid problems of defining the boundaries of the allowable region. A composite plate subjected combined bending and torsion loads is optimized and the results are presented and discussed in terms of practical design of aeronautical structures.