TOPOLOGY AND DAMAGE TOLERANCE OPTIMISATION OF N-219 AIRCRAFT MAIN LANDING GEAR FITTING USING GENERATIVE DESIGN

• Main Author: Rizki Mahalik, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Karya Umum
• Online Access: https://digilib.itb.ac.id/gdl/view/49069
• Institution: Institut Teknologi Bandung

In this thesis, a topology and damage tolerance design optimisation for one of four Main Landing Gear (MLG) fittings on N-219 aircraft was conducted by utilising the Generative Design (GD) technique. GD has revolutionised the method of designing a structural component to attain the optimum component’s geometry while maintaining its structural integrity in withstanding the given loads through several structural optimisation methods, such as sizing, shape, and topology optimisation. The optimisation aims in a weight reduction of the MLG fitting while defending its structural strength and is assisted by OptiStruct in doing so. OptiStruct is an optimisation solver developed by Altair inside their powerful software, the HyperWorks that uses Solid Isotropic Material with Penalization (SIMP) method to complete the optimisation process in achieving almost a very optimum solution. Further processing of the fitting’s geometry was held in a CAD software due to only static loading conditions were applied during the optimisation procedures in OptiStruct. Validating the static strength, a static loading simulation due to the existing load cases for the original and the topology-optimised MLG fitting was conducted using ABAQUS. Also, a convergence test was conducted for both fittings to achieve the correct amount of stresses handled by each fitting under each loading condition. Moreover, since the MLG fitting is one of the Principal Structural Elements (PSEs) of the aircraft, the failure of this component can lead to a catastrophic accident. Hence, a damage tolerance analysis was conducted, as it is essential to determine the service life and the inspection interval of the fitting. Here, the Gross Load (1G-Load) was applied, and Constant-Amplitude (CA) loading method was utilised in both fitting’s crack growth and residual strength examination using MATLAB. The output is useful in determining the inspection interval of the fitting for the importance of the aircraft’s safety, maintenance, and repair. The analysis’ results proved that the implementation of both the topology optimisation and the damage tolerance analysis on the fitting has acceptably reduced the weight of the fitting more than ten per cents while maintaining the compliance to the required static strength and damage tolerance. In addition, the performance in terms of the inspection interval and total service life cycles as a result of the optimisation process between the original and topology-optimised MLG fitting is still comparable with a slight increment of over four per cents.