Mechanical characterization and low-velocity impact behavior of flax woven fabric-reinforced polymer composites

Man–made fibers like carbon or glass are main components for fiber-reinforced polymer composites thanks to their high strength and stiffness values. However, man-made fibers are not eco-friendly and can hardly be recycled in the nature. Using a high amount of man-made fibers threatens our nature and poses a significant risk for the future of world. Natural fiber reinforced composite (NFRC) is considered as a good alternative for traditional composites. Therefore, NFRC has been examined to develop materials, which have comparable mechanical properties with the man-made fiber reinforced composites, for last decades. Although lots of studies were carried out on the mechanics of NFRC, a few of them focused on the structural design of reinforcement and their effects on composites performance. In this study, the number of weft densities of reinforcements were differentiated and their effects on the mechanical properties of composites were investigated. Fabrics were produced from flax yarns and composites were manufactured by vacuum assisted resin infusion molding method. The tensile, compression, shear and impact tests were carried out to characterize the manufactured composites. Results show that while increasing number of weft density of reinforcement improves the tensile and compressive strength of NFRC in the weft direction, the tensile strength and elastic modulus of composites in the warp direction were characterized by the crimp percentage values of warp yarns. Moreover, it was determined that the number of weft density in the reinforcement affect the contact force and energy absorption capacity of NFRC.