Axial crashworthiness performance of foam-based composite structures under extreme temperature conditions

Due to their unique properties, metal foams can be used under extreme temperature conditions. To this end, this paper investigates the influence of temperature (-196, -25, 25 and 250 degrees C) on the axial crashworthiness performance of foam-based composites. The composite structures are made of aluminum thin-walled circular tubes, filled with aluminum alloy (A356) foam. It is found that the highest mechanical characteristics are obtained at the cryogenic temperature (-196 degrees C) due to the hardening behaviour of the matrix material in both foam and tube. Contrary, the softening behaviour of the matrix material at high temperature (250 degrees C) decreases the mechanical properties of the composite material. Between two extreme temperatures, a transition from brittle-to-ductile deformation occurs. The deformation transition is observed both on the stress-strain curves (gradual reduction of oscillations of the plateau region) and the macroscopic images of the compressed samples (changing the crushing mode from non-axisymmetric Diamond Concertina ). Moreover, due to the foam-tube interaction effect, the experimental results show that the quasi-static compressive behavior and collapse mechanisms of the composite structures has considerably improved (over 50% in some cases). Furthermore, the strength properties and energy absorption performances of the foam filled tube shows significantly higher values (almost double) compare to empty one.