Flexural performance and cost efficiency of carbon/basalt/glass hybrid FRP composite laminates

This study investigates the interply hybridization of carbon fibre reinforced polymer (CFRP) composite laminate to improve the flexural performance and cost efficiency. Carbon layers were replaced partially by basalt and/or glass fibres to explore the effects of hybrid ratio and stacking sequence on the flexural behavior and material usage. Hybrid laminates were manufactured by vacuum assisted resin transfer molding (VARTM) process. Three-point bending tests were carried out to characterize the flexural properties and failure mechanisms of the hybrid composite laminates. The fracture surfaces were examined by scanning electron microscopy (SEM). The results showed that flexural strength and modulus of the hybrid laminates decreased with the increase in the hybrid ratio of basalt fibres ranging from 0 to 50%; however negligible effects on flexural properties were observed when hybrid ratio increased further up to 75%. For the hybrid samples, a higher flexural modulus can be obtained by placing carbon layers on the both tensile and compressive sides symmetrically; and a higher flexural strength can be achieved by placing basalt or glass fibre through a sandwich-like stacking sequence with a hybrid ratio of 50%. The finite element modeling and classic laminate theory (CLT) analysis were also conducted through validation against the experimental results, which enabled to reveal the details of strain, damage and fracture under bending. The study exhibited a better material efficiency for glass/carbon hybrid laminates in terms of strength/cost and modulus/cost ratio; and the benefits of such cost efficiency of hybridization were discussed in depth for potential engineering applications.