Flexural properties of notched carbon-aramid hybrid composite laminates

Hybrid composite laminates are currently receiving researchers' attention due to their specific advantages in designing laminates with improved specific strength and stiffness. One of the main disadvantages of polymeric laminated composites is their high sensitivity to notches, which cannot be avoided in design. This paper presents a comparison between two common hybridization techniques, namely sandwich and intra-ply hybridization. The study adopts experimental observations to investigate the influence of hybridization method on the flexural properties of notched carbon-aramid hybrid laminates. After four-point bending tests, the results show that the damage nature in both laminates is different. A catastrophic damage is observed for intra-ply hybrid laminates, while sandwich laminates show progressive damage. In terms of the strength, sandwich specimens show 1.3 times higher specific strength, compared to intra-ply specimens. Moreover, the bottom layers of the laminate manufactured in the sandwich fashion show minimal damage due to the high capability of the aramid/epoxy core to absorb the energy in deformation and concentrate the damage at the top layers (the compression side).