High performance metallic compression panels: assessment of weight reduction obtained by using advanced aluminum alloys and optimum geometry

Integrally stiffened panels for upper wing applicat ion made of aluminum alloys are subjected to pure compression loading. A numerical procedure based on finite-element and analytical simulations is set to determine the opti mum shape and therefore minimum weight of the structure. The influence of the material co mpression behavior, the stringer shape, the stringer pitch and a longitudinal friction stir wel d is assessed by simulations and experiments. The axial compressive load flow (load per unit width) is either 1750 N/mm or 4400 N/mm which covers up to short range aircrafts. Use of AIRWARE ™ ™ materials combined with optimized designs makes it possible t o reach a weight reduction of 24% compared with standard design with 7050 T7451 material on both load flows. Based on ten tests, a fair agreement is obtained between simulat ions and experiments. Test results are very reproducible. A longitudinal friction stir we ld has no influence on the collapse load. At low load flow, design has the largest impact on wei ght reduction, in particular reduced stringer pitch. On the contrary, at high load flow , the largest gain comes from the use of high strength, low density alloy (AIRWARE ™).