An experimental investigation on the effect of strain rate on the behaviour of bare and foam-filled aluminium honeycombs

The effects of strain rate (in low-strain rate regime) on the compressive mechanical behaviour of bare and foam-filled honeycomb structures are experimentally investigated in this paper. Empirical tests show that unlike the existing theoretical formula for bare hexagonal honeycombs, the mean crushing strength of these structures is highly dependent on the strain rate, as an increase of the strain rate yields an increase in the mean crushing strength of up to 40% in some specimens. This effect would be less considerable when it comes to the case of foam-filled panels. The results also indicate that the strain rate has no effect on the densification strain but could change the plane of deformation and increase the number of folds, and consequently decrease their wavelengths.