Compressive deformation and energy absorbing characteristic of foamed aluminum

Abstract

Experiments were carried out to investigate the deformation and energy absorbing characteristics and mechanisms of foamed aluminum (FA) with two different matrices. Some new results were obtained. It is found that, like other cellular solid materials, FA has a stress-strain curve with three distinct regions, i.e., the linear elasticity region, the plastic collapse region or brittle crushing region, and the densification region. The energy absorbing capacity of FA increases by increasing the relative density and the yielding strength. Brittle foam exhibits higher capacity than plastic foam with similar yielding strengths. FA reaches its peak value of energy absorbing efficiency at the strain of about 0.15 to 0.35, depending on the relative density. AlMg10 foam shows higher absorbing capacity and efficiency than Al foam.

Deformation of open-cell aluminum foam

“…In the limit as n→0, the analysis in Section 4.2 predicts (as it should) that the curvature of a deflecting beam is localized near the nodes (fixed ends), and that equation (14) reduces to equation (23) with Cෂ0. 47. This value agrees with the experimentally determined value proposed by Ashby and Gibson for open-cellular (non-metal) materials.…”

“…The flow stress of bulk aluminum is dependent on parameters such as level of impurities, grain size, cell size and dislocation density [36][37][38], but nϷ0.26 is consistent with reports in the literature for high-purity bulk aluminum at strains greater than about 3% [39][40][41][42]. Although metallic foams studied in the literature often display a flow curve characterized by a constant flow stress over a wide range of strains (the so-called plateau stress) [1,2,23,31,43,44], strain hardening similar to that observed in this study is also evident in a few prior studies of foams made from relatively ductile metals such as nominally pure aluminum and low-alloyed aluminum [43][44][45][46][47]. The experimental data, thus, agree at low strains with the analysis in Section 4.2 and are consistent with earlier results.…”

Optimisation of compaction and liquid-state sintering in sintering and dissolution process for manufacturing Al foams

“…A large number of micro pores or interstices are dispersed over the cell walls and form numerous channels between the cells. This unique microstructure suggests, according to the previous studies [3,16,17], that the Al foams made by SDP may have lower mechanical properties but much improved damping and energy absorption capacity.…”

High resolution simulations of energy absorption in dynamically loaded cellular structures

“…Knowledge of the particle velocity distribution in the impactor and target allows the kinetic energies (KE) of the impactor and target to be derived. Assuming the density of the steel is 7.9 g cm −3 , and that the flyer measures 0.6 cm wide × 1.8 cm long and extends 1 cm into the page, the volume of the flyer is 1.08 cm 3 and its mass, m, is 8.532 g. The initial kinetic energy of the flyer, E 300 , is given by…”

“…A variety of cellular structures have been investigated with the aim of improving understanding of compressive response and thus maximising energy absorption over a range of representative impact conditions. These include metal [3][4][5] and polymeric [6][7][8][9] foams, composites [10][11][12] and honeycombs [13][14][15]. One notable feature of this class of materials is the enhance-ment of crushing strength observed under dynamic loading due to inertial effects, as seen by Reid and Peng [16] in wood, Tan et al [17] in aluminium foams and Xue and Hutchinson [18] and Wu and Jiang [19] in metallic honeycombs.…”