EVALUATION OF SHORT-BEAM SHEAR STRENGTH, ACOUSTIC AND VIBRATIONAL PERFORMANCE OF CHEMICALLY TREATED BANANA FIBER REINFORCED CARBON–KEVLAR HYBRID COMPOSITES

Abstract

This study results in evaluation of short-beam shear strength, acoustic and vibrational performance of chemically treated banana fiber reinforced carbon–kevlar hybrid composites. Banana fibers were treated with 5 %  and 0.5 %  to improve fiber surface characteristics and interfacial bonding within a sandwich laminate of carbon–Kevlar intra-ply skins and banana fiber core fabricated by hand lay-up and compression moulding. Short-beam shear strength (SBSS) increased from 14.27 MPa in untreated composites to 17.65 MPa and 19.52 MPa with  and  treatments, respectively, due to enhanced fiber matrix adhesion and removal of surface impurities. Vibrational analysis showed untreated composites had low stiffness (7780.23 N/m) and damping ratio (0.00716), whereas  treatment increased stiffness (9480.51 N/m) and natural frequency (28.68 Hz), improving rigidity and moderate damping. -treatment yielded the highest damping ratio (0.0557) with reduced stiffness, favouring vibration energy dissipation. Acoustic tests revealed -treated composites have superior sound transmission loss across low to middle frequencies, peaking at 15.5 dB at 50 Hz, indicating effective acoustic insulation linked to better mechanical damping. Scanning electron microscopy confirmed enhanced fiber impregnation and fewer defects after treatments. These findings highlight the significant role of chemical surface modification in optimizing structural integrity, vibration control, and acoustic insulation in sustainable banana fiber/carbon–Kevlar hybrids. The improved multifunctional properties suggest promising applications in aerospace, automotive, and structural fields requiring lightweight, durable, and sound-mitigating materials.