Influence of Surface Modification on the Vibration Characteristics of Natural Woven Banana-Jute Fiber Reinforced Hybrid Composites

Objectives: To analyze the vibration behavior of jute and banana fiber reinforced hybrid composites subjected to surface modification with sodium hydroxide (NaOH) and subsequent polylactic acid (PLA) coating, using both experimental method and Finite Element Analysis (FEA). Methods: In the present work, hybrid bio-composite laminates were developed using a hand-layup method with compression molding technique. Six different laminate configurations were prepared by varying the stacking sequence and surface modification of jute and banana mats to investigate the vibration characteristics. Experimental modal analysis and numerical simulation using ANSYS were employed to analyze the natural frequencies of the composites under various boundary conditions, including Simply Supported (SS), Clamped-Clamped (CC), and Clamped-Free (CF). The influence of ply orientation on natural frequency was also analyzed under SS and CC conditions. Findings: From the experimentation and FEA, it is found that chemical treatment and coating improves free vibration properties of composites due to the enhancement of interfacial bond between fiber and matrix. The hybrid composite beam BJ3 exhibited 8.89%, 21.52%, 6.48%, 21.14%, and 37.21% higher fundamental natural frequencies than BJ2, BJ1, JB3, JB2, and JB1, respectively. FEA results showed excellent predictive capability with errors consistently below 5%, suggesting that the numerical models are reliable tools for estimating the vibrational response of such hybrid composites. The study underscored the pivotal influence of ply orientation on natural frequencies, with the 0° orientation excelling in specific end conditions. Novelty: In this study, woven jute and banana fibers were subjected to eco-friendly surface modifications i.e. alkali (NaOH) treatment and PLA coating, which enhances fiber–matrix interfacial bonding. As a result, the developed natural fiber-reinforced composites exhibited improved mechanical performance, making them suitable for medium-strength applications in sectors i.e. automotive components, construction materials, and sustainable packaging. Keywords: Jute and Banana Hybrid Composites, Polylactic Acid Coating, NaOH treatment, Free Vibration characteristics, Finite Element Analysis