Mechanical Characterization and TOPSIS-Based Selection of Hybrid Natural Fiber-Cenosphere Reinforced Polymer Composites for Automotive Structures

This study evaluates a novel composite material for automobile structural applications, consisting of a polymer-based matrix material reinforced with hybrid natural fibers (Jute, Kenaf, Coir) and cenospheres. Natural fibers provide sustainability and lightweight benefits, while cenospheres enhance mechanical properties and reduce density. We assess tensile, flexural, and impact strengths, examining the effects of 2 vol% and 4 vol% cenosphere concentrations. Scanning electron microscopy analyzes microstructural features and interfacial bonding. Results indicate that kenaf-reinforced laminates exhibit an 86.36% higher tensile strength than jute and are 2.73 times stronger than coir composites. While 2% cenosphere enhances tensile and flexural properties, 4% improves impact strength across all composites. Notably, 2% cenosphere boosts tensile strength by 28%, 23.4%, and 28.57% for jute, kenaf, and coir, respectively. Our findings highlight the synergistic effects of hybrid fibers and cenosphere reinforcements, with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) approach identifying the Kenaf/Epoxy composite with 4 vol% cenosphere as the superior option for practical applications. This research contributes innovative, sustainable solutions for enhancing automotive structural performance while minimizing weight.