Analysis of fracture characteristics in aluminium-CFRP hybrid laminate subject to three-point bending loading

Fibre metal laminates represent a family of hybrid laminates with interesting mechanical properties, due to their lightness. Flexural loads are very frequent in structural parts; therefore, the investigation of the failure mode and the fracture behaviour connected to this loading state is crucial, and it constitutes the core of the present work, in which the effect of the metal-composite material interface type on the fracture mode was investigated. Some specimens were produced considering two different types of interfaces: in the first case the bonding of the aluminium sheets to the CFRP was guaranteed by structural adhesive, in the second case no adhesive was used, relying on the prepreg resin bonding capabilities. The produced samples were tested according to the three-point bending procedure, varying the support span, and the fracture surface morphology was analysed. It was found that the presence of the adhesive influenced the fracture mode and the resultant fracture surface morphology.