Free Material Optimization of Multilayer Composite Materials

Abstract

The use of composite materials in various types of devices has increased steadily in the past decades. Hence, it is worth investigating into the structural behaviour of these materials. The optimization of stacking sequences in multilayer composite materials opens a large field of improvements in industrial applications of composite materials. The center of investigation is set on fiber reinforced laminate plies, which are examined in the case of linear anisotropic theory of elasticity. One very auspicious way for optimization of these laminates is the implementation of Free Material Optimization (FMO). In these optimization procedures arbitrary values of parameters of the elasticity matrix are obtained under constraints which only claim the elasticity matrix to be symmetric and positive semidefinite. Also the trace of the elasticity matrix is restricted to avoid the total stiffness of the material to get unnaturally large. The sensitivity information are received by the variational approach for sensitivity analysis [1] which represents the most efficient known way of computing sensitivity information.