Experimental investigation and TOPSIS-based multi-criteria selection of sisal/glass hybrid composite boat floors with different fiber sizes, architectures, and stacking sequences

This study investigates the mechanical and physical performance of hybrid sisal/E-glass fiber-reinforced polyester composite laminates for potential boat floor applications. Nine laminates were fabricated using three fiber configurations (unidirectional, woven, and chopped) and three stacking sequences glass-sisal-sisal-glass (G-S-S-G), sisal-glass-sisal-glass (S-G-S-G), sisal-sisal-glass-glass (S-S-G-G). Alkali-treated sisal fibers were extracted from Ethiopian-grown plants, and compression molding was used for composite fabrication. Mechanical tests including tensile, flexural, compressive, and impact strength, as well as water absorption and density measurements, were conducted in accordance with ASTM and ISO standards. Results showed that unidirectional laminates, especially with G-S-S-G stacking, achieved the highest overall performance achieving tensile strength of 203.1 MPa, flexural strength of 237.3 MPa, compressive strength of 58.83 MPa), and impact strength of 146.84 MPa while also demonstrating the lowest water absorption rate of 2.64%. Multi-criteria optimization using AHP-TOPSIS ranked this configuration (M1) as the most suitable for boat floors due to its superior mechanical behavior and environmental resilience. This research highlights the potential of sisal/glass hybrid composites as sustainable, cost-effective alternatives to conventional materials in marine applications.