Mechanical performance and python-based TOPSIS ranking of carbon-filled Kevlar/Basalt/S-glass hybrid epoxy composites for automotive structural applications

The increasing requirement for lightweight and high-performance materials in the automotive industry has prompted significant research efforts focused on hybrid fiber-reinforced polymer composites. This study looked at making and carefully testing epoxy-based composites that were strengthened with Kevlar, basalt, and S-glass fibers, using 10% carbon powder as an added material. The study created single-fiber, dual-fiber hybrid, and tri-fiber hybrid laminates using the hand lay-up method, which allowed for controlled stacking sequences. Mechanical characterization was conducted following ASTM standards, encompassing tensile, flexural, impact, and hardness evaluations. The results show that using a mix of different fibers significantly improves mechanical properties compared to using just one type of fiber. Specifically, the basalt-Kevlar-S-glass tri-hybrid composite demonstrated a peak tensile strength of 354.37 N/mm², an outstanding flexural strength of 1350 N/mm², a maximum energy absorption capacity of 7.2 J, and the highest hardness level recorded at 115 RHN. These metrics reflect an exceptional ability to bear loads, resist bending, tolerate impacts, and maintain surface durability. The better performance is mainly due to how well the materials work together, the strong connections between the fibers and the matrix, and the added strength from the carbon filler. To support the experimental results, a TOPSIS analysis was done using Python, treating all criteria equally. The tri-hybrid composite demonstrated the highest closeness coefficient (CC = 1.000), thereby affirming its preeminence. The hybrid composites formulated exhibit significant promise for applications in lightweight automotive structures, specifically in the context of roof panels and load-bearing elements.