Al-Li alloys that can be used in F-5 aircraft structures and an application example

In the aerospace industry, where material properties such as lightness and low cost are very important as well as high material properties, traditional Aluminium-Copper alloys have a very large and important place because they meet these criteria. These materials, which have been used for many years, are a group of materials that have proven that they can meet the demands of the sector. On the other hand, Aluminium-Lithium (Al-Li) based alloys, which have been under development for many years and have significant advantages today, are an important competitor and alternative to traditional aluminium alloys. The weight advantage of lithium being the lightest metal element, high strength properties and lower costs compared to composite materials make this alloy group attractive in the sector and preferred over composites. In this thesis, starting from the history of Al-Li alloys, a comparison of the 3rd generation Al-Li alloys was made, the material properties of 2099-T8E67 and 2024-T6 alloys were examined in detail and a comparison of these two materials was made. Within the scope of this comparison, 21% spar on the wing of the F-5 fighter aircraft was used. The spar was first modelled with Solidworks and then static structural, fatigue and vibration (modal) analyses were carried out on this spar by defining 2024-T6 and 2099-T8E67 materials using the 'Finite Element Method' with ANSYS program. The results obtained are shared and evaluations and recommendations are made in the last section. As a result of the analyses, it was seen that 2099 alloy has the potential to be considered as a good alternative with the necessary strength properties that can be used in F-5 wing spar instead of 2024 alloy.