A design study was conducted to determine the potential weight savings and performance increase from advanced metallic materials for wing skin panels. The materials included aluminum lithium 2090-T83, ARALL-3 (aramid-reinforced aluminum laminate) and GLARE-2 (glass-aluminum-reinforced epoxy). An executive business jet airplane was taken as a baseline in the design trade study. This wing has mechanically attached stringers to stiffen the panel against compressive and shear loading. The advanced skin materials were designed into an advanced wing box; advantage was taken of the increase in strength and stiffness. The design, fabrication, and testing of the test panels were done at Textron Aerostructures. Two 2090-T83 aluminum-lithium skins with 7075-T6511 extruded Z-shaped stringers bonded to them were used for the evaluation of the upper wing cover structure. One panel had five bays, the other four. The respective widths were 59.39 cm (23.38 in.) and 49.48 cm (19.48 in.). The overall length was 125.43 cm (49.38 in.) for all panels. Two ARALL-3 and two GLARE-2 compression panels with the same type of stringers were designed to evaluate the lower wing cover structure. The laminate panels were all five-stringer bays 78.74 cm (31 in.) in width.
The study confirmed that a weight savings in the order of 10 to 15% can be achieved with panels made with these advanced materials. The compression tests showed that all test panels failed in column bending and the predicted critical loads compared to those from the tests were conservative. The tests also validated the design methodology.