Impact resistance and bonding capability of sandwich panels with fibre-metal laminate skins and aluminium foam core

Sandwich panels with aluminium foam core and fibre-metal laminate (FML) skins for enhanced impact resistance have been designed and manufactured during this research activity. The FML skins are made of a combination of aluminium sheets and E-glass fibre/epoxy-laminated plies. Drop-weight impact tests are conducted on two groups of sandwich panels with aluminium foam core bonded to the aluminium sheet in Group 1 panels, and aluminium foam core bonded to the E-glass/epoxy ply in Group 2 panels to allow an investigation of the bonding capability between the aluminium foam and the FML skins under impact and the impact resistance of the sandwich panels. The delamination and debonding ranges, the maximum deformed height in the impact area are measured and the deformed volumes of the sandwich panels after drop-weight tests are evaluated. via comparison of these parameters for the two groups of sandwich panels, it is found that the bonding between aluminium foam to the E-glass/epoxy surface provides a better resistance to impact than that between aluminium foam bonded to the aluminium sheet of the FML facing, and that overall Group 2 panels exhibit better bonding capability and impact resistance with less facing delamination and core/facing debonding than the Group 1 panels.