Experimental characterization and predictive modeling of hybrid deviation in glass/jute/banana polymer composites

This study prepares and compares three hybrid polymer matrix composites (PMCs) reinforced with glass, banana, and jute fibers via hand lay-up, with 20 wt.% total fiber content in epoxy (Araldite LY556/HY951). Three formulations were tested for Specimen 1 (10% glass + 10% banana), Specimen 2 (10% glass + 10% jute), and Specimen 3 (10% glass + 5% jute + 5% banana). Tensile (ASTM D3039) and flexural (ASTM D7264) tests revealed Specimen 2 achieved the highest tensile (122.0 MPa) and flexural strength (63.56 MPa) due to effective glass-jute stress transfer. Specimen 3 showed intermediate strength (92.9 MPa tensile, 54.67 MPa flexural), while Specimen 1 had the lowest (81.6 MPa tensile, 50.22 MPa flexural) due to banana fiber hydrophilicity and poor matrix bonding. Break distances (2.64 mm, 3.56 mm, 2.09 mm) indicated reduced ductility in the ternary hybrid. Gaussian Process Regression (GPR) predicted properties from fiber composition. The hybrid deviation index confirmed negative synergy for Specimen 3. Constant 20 wt.% total reinforcement design isolating fiber-type effects from fiber-content effects, Hybrid deviation index quantifying negative synergy for the ternary laminate, and GPR as an exploratory interpolation tool specifically for small-sample (N=3 formulation classes) hybrid composites. Mechanical variations reflect microstructural factors including non-uniform fiber distribution and void content. The glass/jute hybrid demonstrates balanced properties suitable for semi-structural applications like lightweight panels and automotive components.