AIRCRAFT SUBFLOOR STRUCTURE OPTIMIZATION USING AUXETIC METASTRUCTURE FOR IMPACT ENERGY ABSROPTION

• Main Author: Pridhanie Salim, Andaffatama
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68431
• Institution: Institut Teknologi Bandung

<p align="justify"> Indonesia is growing rapidly in Aerospace Industry domestically. Crashworthy aircraft is needed to ensure safety for users along the country. Aircraft subfloor is designed to absorb impact energy especially during take-off and landing crash events. Aircraft subfloor structure with the base of auxetic metastructure is studied due to its light weight and ability to absorb impact energy because of its negative poisson’s ratio. The ability of absorbing impact energy is done by using finite element methods to find the optimum Specific Energy Absorption (SEA). The optimization process of the auxetic metastructure is done using the Taguchi’s Method to determine the optimum configuration for SEA. There are four control factors (shape geometry, width, angle, and material) used with three levels for each factor used in the optimization process. Analysis of Variance (ANOVA) is also done with the output to determine the sensitivity of the structure to each control factor. There are three types of shape geometry that is used in the optimization process which are Re-entrant, Double-Arrowed Auxetic (DAA), and Double-U Honeycomb (DUH). Besides that, three types of materials are used which are Alumunium 7075, nylon polymer, and Carbon Fiber Reinforced Plastic (CFRP). The ANOVA results in material being the most contributing factor of the optimization. The optimization results which consist of re-entrant shape, 20 mm width, 60° angle, and Al7075 material will be used in an aircraft subfloor model which is used in the rear fuselage of the Airbus A320. The drop-weight test is done with the initial velocity of 13 m/s and the result of the simulation, the energy absorption will be compared between both the baseline model and the optimized model with the auxetic structure. The simulation results show that for the subfloor model with Re-entrant auxetic structure, the generated SEA value is 0.66 kJ/kg. The value increased from the baseline model as big as 10.41%, this shows that the Re-entrant auxetic structure may be a new alternative as an impact energy absorber for aircrafts.