Optimization of Composite Wing Structures for Maximum Flutter Speed

Abstract

†‡ This paper is aimed at investigating aeroelastic tailoring of composite wing structures for maximum flutter speed by using different optimization methods. A gradient -based deterministic method (GBDM) and ge netic algorithm (GA) have been employed in the investigation. It has been noted from previous research that a significant increase in flutter speed can be achieved by tailoring the fiber orientations of a composite wing box structure using the former metho d. However the solution largely depends upon the initial laminate lay -up. The current investigation shows that the optimized solution from GA is much less dependent upon the starting lay -up. It is much more robust in searching an optimization solution alth ough more computing time is normally required and a global solution is not guaranteed. Sensitivity of flutter speed to optimized lay -ups has been considered when employing GA. A filter and local search algorithm has been introduced into the GA optimization to assess and identify a feasible solution from the optimized lay -ups. A uniform and a tapered composite wing structure of different swept angles have been considered for demonstration purpose in this paper. The results show that by using the two differen t optimization methods, same level of flutter speed increment but slightly different optimized lay -ups for the wing structures have been achieved.