Weight optimisation of damage resistant composite panels with a posteriori cost evaluation

In the present paper, we attempt a novel optimisation strategy for damage resistant composite stiffened panels based on genetic algorithms and oriented towards the satisfaction of minimum weight criteria. In order to accomplish this task, first, minimum weight solutions for panel configurations with T and I stringers, satisfying the buckling resistance constraint are examined. Some minimum weight solutions are imposed to be buckling resistant only, that is, capable to sustain a given minimum admissible buckling load, while other solutions are imposed to be buckling and damage resistant, in other words, capable to sustain a given admissible buckling load being at the same time able to resist to a given impact energy without developing significant damage. Then a-posteriori evaluation of costs is performed for the best minimum weight solutions. Such an evaluation takes, at the same time, into account the manufacturing costs, which depend on the selected manufacturing process and on the geometrical configuration, and the maintenance costs which are related to impact events and consequent repairing actions. Finally, the influence of the impact damage and buckling resistance constraints on the stiffened composite panel’s costs is critically discussed providing useful considerations oriented to a cost effective composites design.