Weight Reduction and Material Characterization in A Part Used in Aviation Applications Produced by Additive Manufacturing Method

Abstract

Optimizing design in the aviation sector without altering load paths, achieving fuel savings through weight reduction, reducing carbon footprint, and gaining high maneuverability for aircraft through such improvements remain key areas open to continuous development in this field. To achieve these goals, novel technologies are being developed. However, design and production must be compatible with each other in order to attain this goal. Traditional production methods often limit design in terms of producibility. To overcome this situation, topology optimization has emerged as a prominent tool in recent years, in addition to additive manufacturing. Specific constraints and target values are assigned to the component to reduce the weight of the part and improve its stress values compared to the initial design. Additionally, the control of the compliance is taken into account to ensure it remains within a certain stiffness range. In this thesis, optimization was performed on a structural component that already exists in a helicopter. The selected component is made of Al 6061 T62 and is connected through welding. By applying topology optimization to the part, load paths were initially determined,and the material was removed in areas where high stress was not expected, resulting in a total weight reduction of 15.7 %. Modal analysis was conducted to evaluate if the vibration values increased while achieving lightweight. While the initial vibration value was 60 Hz, which was increased to 67 Hz after applying topology optimization with material change for analysis. This vibration analysis is crucial since it affects the lifespan of the component. Simultaneously, AlSi10Mg material, which is one of the most suitable materials for SLM manufacturing method in terms of strength and superior to Al 6061 material, has been subjected to tensile coupon tests. However, this material exhibits different mechanical properties in different directions due to its anisotropic nature. Therefore, the experiments were carried out the SLM method to produce the material in different directions and geometries. Coupon samples were subjected to stress relief, destructive and non-destructive testing, and the characterization of AlSi10Mg material was performed. The obtained results served as input for size and topology optimizations aimed at further reducing the weight of the optimized parts. These optimized designs were then subjected to modal analysis and the resulting natural frequency values were compared with the natural frequencies of the helicopter. According to the static and modal analysis results, it is evident that lower stresses are observed on the optimized part, which has a lighter weight.