Investigation of physio-mechanical properties of luffa-coir natural fiber hybrid composite and optimization of mechanical properties via fuzzy logic approach

This study focuses on the preparation of hybrid composites using natural coir and luffa fibers reinforced in an epoxy resin matrix, followed by an evaluation and optimization of their mechanical properties. Three different fiber combinations are used as prototypes using the hand-lay-up method. Tensile strength, bending resistance, impact testing, hardness, water absorption, and density are all extensively evaluated for materials in accordance with ASTM and ISO standards. The composite with the highest tensile and hardness strengths is composite C with 13.4 MPa and 78.33, respectively, which is made up of 10% luffa and 5% coir. With 5% luffa and 10% coir, the least dense composite A outperforms others in flexural strength (30.83 MPa) and impact energy absorption (186.04 J/m). With a 7.5% split between the two fibers, composite B does reasonably well in every test. The findings indicate a complex relationship—longer fibers decrease bulk density, whereas increased fiber content raises void formation and density, resulting in a nuanced combination of attributes. This work also introduces the Fuzzy model not just as a tool but as an architect of composite materials’ most optimal composition modeling. The adaptive framework of this model has enabled us to create high-performance composites for diverse engineering applications.