Mechanical Performance of Novel Natural/Glass Fiber Blend for Reinforcing Metal Laminates

ABSTRACT This study presents a novel approach to blend natural flax and chopped glass fibers. The fiber blends were in the form of mats with the composition as follows: 25% glass/75% natural fibers (G25/N75), G50/N50, and G75/N25. Mats of 100% natural fiber (N100) and glass fiber (G100) were prepared as benchmark samples. Fiber metal laminates (FMLs, 3/2)—based on hybrid fiber—were fabricated via autoclave method; metallic sheets from aluminium alloy 2024 were used. Quasi‐static mechanical tests including tensile and flexure tests were carried out whereas the Charpy impact test was conducted to represent the low‐velocity impact test. The results confirmed that chopped glass fibers enhance the mechanical performance of FMLs based on natural fibers. The tensile, flexural, and impact strengths of the 100% natural fiber FML (N100) were 109.9, 193.9 MPa, and 196.9 kJ/m ² , respectively. With the incorporation of glass fibers, the mechanical properties steadily improved across hybrid ratios G25/N75, G50/N50, and G75/N25; the maximum values of mechanical properties are recorded for G75/N25‐based FML including 198.5 MPa for tensile strength, 223.2 MPa for flexural strength, and 254.8 kJ/m ² for impact strength. Moreover, a finite element model of the 3‐point bending test for G50/N50‐based composite was developed. Both experimental and numerical models show the fracture in hybrid glass/natural fiber‐based FMLs was due to fiber breakage, matrix/fiber debonding, and plastic deformation extended to the fracture of metal layers. The study promotes manufacturing sustainable composites through the strategic blending of natural and glass fibers, reducing the environmental impact of glass fiber.