Size and shape optimization of aluminum tubes with GFRP honeycomb reinforcements for crashworthy aircraft structures

Abstract

Please cite this article as: Paz, J., Díaz, J., Romera, L., Costas, M., Size and shape optimization of aluminum tubes with GFRP honeycomb reinforcements for crashworthy aircraft structures, Composite Structures (2015), doi: http:// dx. AbstractCrashworthiness optimization of aircraft and automotive structures has become one the main research targets for their respective leading industries. The following research proposes a new design of an aircraft's vertical strut. The design consists of a hollow aluminum square tube with a glass-fiber reinforced polymer honeycomb-shaped inner structure. Size and shape surrogate-based optimization techniques are used, with the thicknesses of both materials, cell size and cell shape as design variables. The objective function chosen for the single-objective optimization is the specific energy absorption, while the metrics for the multi-objective optimization are the peak force, mass, absorbed energy and the specific energy absorption. An improvement of 22% of the specific energy absorption with low peak force values is obtained from the single-objective optimization by significantly changing all design variables. Two Pareto fronts have been obtained from the multi-objective optimization confronting, the specific energy absorption against the peak force and the mass against the energy absorbed. When compared to the baseline model, the optimized models show substantial improvement, increasing the specific energy absorption by 65% or reducing the peak force by over 55%. It has been observed an important effect of the cell shape on the model's performance.

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

“…The GFRP's properties have been extracted from the manufacturer's data sheets 29 as well as from the data recorded from tensile tests 30 . The plasticity model used is adjusted to the polymer's visco-elastic behavior, limiting the maximum true strain at 2.38%, where the material fails.…”

“…For this material, k = 2. Both the aluminum and the GFRP models have been more thoroughly described in Paz et al 30 . Table 2: Material properties of Ultramid A3WG10 BK00564.…”

An Insight on the Crashworthiness Behavior of a Full-Scale Composite Fuselage Section at Different Impact Angles

“…Indeed, the cargo subfloor area first experiences the impact with the ground, absorbing most of the kinetic energy. In particular, the impact energy is absorbed by the frame and the hinges [24][25][26][27][28][29][30][31][32][33]. The fuselage frame can dissipate almost half of the impact energy during the impact.…”

Cluster-Based Optimization of Cellular Materials and Structures for Crashworthiness

“…Models for functionally graded polymeric foams have proposed in order to improve the energy absorption characteristics offered by uniform foams [6]. The application of metal foams in crashworthiness has been increasingly considered as fillers of straight [7][8][9][10] and tapered [11][12][13] thin-walled tubular structures. Most of these studies rely on experimental testing and numerical simulations.…”