Structures et Matériaux utilisés en Aéronautique

Abstract

Internal structures in aeronautical, aircraft or space structures are composed of bar elements or lightweight beams assembled by welding, riveting or bolting of simple or complex geometric shapes. They are covered with lightweight materials such as: Aluminium, composite materials, or adaptable materials. The assembly of all these elements and materials constitutes a structure of high rigidity and high quality of mechanical strength as well as a state of the art very considerable in the field of aeronautics and aerospace. In this context, a presentation of the different materials and their state of the art in the field of the application of aeronautics will be presented. A theoretical analysis and modelling by the finite element method these structures has been studied. This analysis can be performed discretely (element by element) using the method of the bar elements, beam element or plate elements or by continuous models representing the discrete structure and the material that covers it. An analysis of the stresses in the main parts of the aircraft was presented for different types of materials and internal structures of aircraft wings in the static state. Experimental and numerical characterizations of nanoparticles bonded joints typically used in aerospace applications are presented. First, samples of single-lap joints produced using a composite reinforced with carbon fibre fabric (2% graphéne by weight), were analysed. Shear tests were performed to measure the resistances of the bonded joints, to assess the structural performances of the structures with and without nanoparticles. Second, finite-element numerical models were applied based on experiments on adhesive joints; in particular a numerical simulation of the adhesive lap-joint model was performed using ANSYS software. Analyses were performed for the joints with unfilled and nanoparticles adhesive, focusing on the cooling process during which adhesive single-lap joints are mainly generated. The experimental and numerical model results generally agree quite well. The nanoparticles of the Graphéne increased the stiffness of each lap joint under a rational load charge. The nanostructure adhesive increased the failure load, but this increase depended on various parameters, including adhesive structural features and the structures of the nanostructures produced. The reinforced adhesive nanostructure was found to decrease the weight.