Experimental optimization of flexural behaviour through inter-ply fibre hybridization in FRP composite

• Effect of stacking sequence on the flexural behaviour of inter-ply hybrid composite.
• With only 0.51 hybrid ratio the strength becomes 96% of pure CE composite.
• Catastrophic failure is dominant for composites with carbon fibre at the tensile end.
• Prominent failure in CE and GE plies are fibre fracture and delamination respectively.

Inter-ply fibre hybridization is one of the promising techniques to improve the mechanical properties of a laminated FRP composite, but the mechanical response of these hybrid composites under a flexural kind of complex loading is not fully explored experimentally. Present investigation is focused to improve the flexural properties of a glass/epoxy (GE) composite by replacing some of the GE plies by equal No. of carbon/epoxy (CE) plies at different locations. In the 7 layered composite, replacing 2 GE plies at each ends of a GE composite resulted in a hybrid composite (C2G3C2) having 93% modulus and 96% strength as that of a C7 composite. Presence of CE plies at the tensile side leads to enhanced strength and modulus but at the same time makes the hybrid more prone to catastrophic failure. Whereas, placing the entire CE plies at the compressive side yielded progressive failure behaviour similar to that observed in the GE composite. To understand the failure mechanisms of GE and CE plies in different composite systems their fractured surfaces were studied by SEM.