Tensile and flexural behavior of synthetic and hybrid natural fiber composites for lightweight applications

The growing demand for lightweight and sustainable materials has driven research into hybrid composites that combine synthetic and natural fibers. This study aims to investigate the tensile and flexural behavior of carbon fiber (CF) and glass fiber (GF) composites, alongside hybrid composites incorporating flax and hemp fibers. The composites were fabricated using the vacuum bagging technique, ensuring uniform fiber distribution and optimized mechanical properties. Experimental results revealed that CF composites exhibited the highest ultimate tensile strength (~550 MPa), with failure dominated by matrix cracking and fiber breakage due to their inherent brittleness. GF composites, while having a lower tensile strength (~450 MPa), demonstrated greater ductility, attributed to fiber pull-out and matrix cracking. Hybrid composites (H1), combining CF and GF, showed intermediate tensile strength (~500 MPa), reflecting mixed failure modes. In contrast, natural fiber composites (FH and H2) displayed significantly lower strengths (~150–200 MPa) due to weaker fiber-matrix interactions and moisture sensitivity. Despite their lower strength, hybrid composites provided a balance between mechanical performance and sustainability, making them a promising alternative for lightweight structural applications in automotive, aerospace, and eco-friendly engineering. These findings highlight the potential of hybrid composites in reducing environmental impact while maintaining structural integrity, offering a viable solution for next-generation sustainable materials. Highlights: CF, GF, H1, FH, and H2 composites were prepared through vacuum bagging. CF showed strength (~550 MPa) with brittle failure; GF was ductile and moderate. H1 hybrids combined CF and GF for balanced performance at ~500 MPa. Natural fiber composites prioritize sustainability with lower strength. H2 hybrids offer a mix of eco-friendliness and improved durability.