Mechanical Performance and Energy Absorption Characteristics of Sustainable Bio-based Luffa/Woven Carbon Fabric Hybrid Epoxy Composites

Abstract

Mechanical behavior was tested for hybrid composites with natural luffa fiber and artificial woven carbon fabrics within an epoxy matrix with orientation angles of [90°], [45°], and [0/90°]. Specimens were produced with artificial and natural fibers in a four-layer configuration. Three-point bending, tensile, and low-speed impact tests were applied. In tensile tests, specimen [0/90º Carbon - Luffa - Luffa - 0/90º Carbon] exhibited the highest strength, reaching approximately 42 MPa. In three-point bending tests, specimen [0/90º Carbon - Luffa - Luffa - 0/90º Carbon] showed the highest force of approximately 120 N. In low-speed impact tests, at an impact energy of 5 J, the impactor rebounded without penetrating any of the specimens. At an impact energy of 15 J, punctures and fiber damage occurred in samples [90º Carbon - Luffa - Luffa - 90º Carbon] and [45º Carbon - Luffa - Luffa - 45º Carbon]. In contrast, sample [0/90º Carbon - Luffa - Luffa - 0/90º Carbon] reached maximum force values of approximately 6000 N at 15 J impact energy and approximately 3500 N at 5 J impact energy, exhibiting higher impact resistance without puncture. Based on these results, the woven carbon fabric orientation angle had a decisive effect on the bending, tensile, and impact behavior of hybrid composites.