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.

This research concerns the crashworthiness study and enhancement of commercial aircraft fuselage structures by incorporating crushable hybrid energy absorbers to work as vertical struts. To assess their contribution on a representative aircraft structure, a numerical simulation of a Boeing 737-200 drop test is developed and validated with experimental data available in the literature. The fuselage section is then simulated both with and without the fuel tank, showing more harmful effects for the latter scenario. The numerical model accurately captures the experiment’s collapse process with low artificial energy ratios. Later, four vertical hybrid energy absorbers designed for programmed and progressive collapse, are added in the cargo compartment, connecting the underfloor beams and the frames. Different designs and positions are studied, combining aluminum tubes with square and circular cross-sections, filled with a core made from a GFRP skeleton and foam extrusions. Acceleration graphs show a reduction in passenger injury levels from severe to moderate according to an Eiband diagram when energy absorbers are fitted. Energy trends from the hybrid absorbers are also monitored, with dissipation of up to 10 kJ of the fuselage’s kinetic energy through plastic deformation and collapse. Results also show a significant improvement on the global crashworthiness of the fuselage, leading to an increase in plastic dissipation by the frames from 76 kJ to 122 kJ and a reduction on the accelerations up to 50% when the energy-absorbing structures are added.

This research focuses on the crashworthiness study and enhancement of commercial aircraft structures by developing crushable energy absorbers to work as vertical struts (stanchions). To assess thei...