Numerical investigation on aircraft wing stiffener composite material integration

Abstract

The reduction of the aircraft weight is a great challenge for constructors, allowing them to cut down on fuel consumption and to increase the load carrying. This can be achieved by improving the properties of materials of aircraft parts. One of the most massive parts is the wing itself. In fact, according to a recent review of Aircraft Wing Mass Estimation Methods made by Dababneha and Kipouros (Aerosp Sci Technol, https://doi.org/10.1016/j.ast.2017.11.006, 2017) an aircraft wing could reach 8811 kg (Megson in Aircraft structure for engineering students, 3rd edn. Arnold, London, (1999) for an Airbus A320-200 and even 39,914 kg (Anderson in Fundamentals of aerodynamic, 3rd edn. McGraw-Hill, Boston, 1999) for a Boeing 747-100 since it is a long-range aircraft. Thus, it seems very interesting to act upon the material choice of wing components but without harming structure stiffness. In fact, composite integration has a direct impact on the stress and the weight of the wing which matters a lot in the conception of an aircraft wing. Such a complex problem requires indeed a multidisciplinary approach based on aerodynamics and structural analysis of both composite material and aluminum alloy. Solving this problem could be of great interest for both industrialists and researchers since it would lighten the path towards full composite wing integration. In this work, we propose a double-approach numerical method to study the effect of different composite materials integrated into aircraft wing skin stiffeners. By this way, this investigation aims to show the improvement given by composite materials to the structure and the achieved mass reduction after cautious integration, taking into consideration the stiffness of structure after load application. It also gives a method based on the best yield on weight ratio to compare the different possibilities of integrations to choose the most relevant material, its stacking and fibers orientations. For that, we relied on both analytical calculation and finite element analysis. A Matlab code was developed to determine structure response to loading such as longitudinal and shear stress and to estimate the global structure’s weight for different materials. We started by working on a wing made from the aluminum alloy AA2024 and then we integrated various composite materials like Glass fiber, S-glass/epoxy, and hm graphite/epoxy. Also, an investigation of the variability of stacking sequences and plies orientations was undertaken. As a result, we obtained a clear assessment of the potential of each material. We finally created, inspired by the Airbus technical data, an accurate finite-element model of an aircraft’s wing that served to study the structural resistance with Abaqus. Coherent results for the selected composite material and for its ply’s stacking and orientation were found.