Crashworthiness Optimization of Aircraft Hybrid Energy Absorbers Enclosing Honeycomb and Foam Structures

Abstract

This research proposes a new design for a vertical strut used in aircraft fuselages. It consists of a hollow aluminum vertical strut filled with a glass-fiber-reinforced polymer honeycomb-shaped structure and polymeric foam. The design is optimized for crashworthiness of aircraft fuselage structures. The variables of the surrogate-based optimization procedures are the thicknesses of the aluminum and polymer, and the cell size and shape. The objective functions for the single-objective optimization are the specific energy absorption and the cost, whereas the metrics for the multiobjective optimization are the two aforementioned along with the peak force, mass, and absorbed energy. By using the polymeric foam, an improvement of 28% on the specific energy absorption is obtained when compared to a component without this reinforcement. Compared to a baseline model, the optimum also reduces the cost by 40%. Three Pareto fronts are obtained with different combinations of objective functions. When compared to different baseline models, the optimized models show substantial improvement, increasing the specific energy absorption while reducing peak force, mass, and costs. An important effect of the cell shape on the model’s performance is observed, with the optimum models having pseudorectangular cells.