PSI - Issue 70

Karthick Rasu et al. / Procedia Structural Integrity 70 (2025) 619–626

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Fig. 1. Fabrication process of composites

2.3. Mechanical properties The mechanical properties of the hybrid composites were evaluated to assess their performance under various stress conditions. Tensile, flexural, impact, and hardness tests were conducted to evaluate the mechanical properties of the composites. Tensile tests, conducted according to ASTM D3039 standards, determined the maximum stress the composites could withstand while being stretched, providing insights into their resistance to deformation under tensile forces. Flexural strength, assessed per ASTM D7264, revealed the composites' ability to resist bending forces, which is important for structural applications. Impact strength, measured by ASTM D256 standards, indicated the toughness of the composites, reflecting their resistance to sudden impacts or shocks. The Rockwell hardness test, performed according to ASTM D785, evaluated the composites' resistance to surface deformation or indentation, important for applications involving abrasion or surface wear. The mechanical behaviours of the composites, with changing fiber content (Banana, Coir, and Jute), were compared to understand how each fiber type influenced the overall performance. This data helps in selecting the optimal fiber combinations and volume fractions for specific applications. Fig. 2 presents the tensile behaviour of the fabricated composites. The tensile strength values of the samples, ranging from 43.42 MPa (Sample 1) to 56.63 MPa (Sample 4), indicate variability in their mechanical performance. This variation can be attributed to differences in the fiber combination and distribution, which directly impact material properties. Sample 1, composed of 50% banana fiber and 50% coir fiber, shows the lowest tensile strength, possibly due to weaker bonding and stress distribution. In contrast, Sample 4, with a combination of 40% banana fiber, 30% coir fiber, and 30% jute fiber, exhibits the highest tensile strength, suggesting optimal fiber synergy and reinforcement within the epoxy resin matrix. The general increase in tensile strength from Sample 1 to Sample 4, followed by a slight drop in Sample 5 (33% banana, 33% coir, and 34% jute), highlights the influence of fiber combinations and processing parameters. The uniform fiber volume fraction (60%) across all samples ensures consistency in fiber-matrix interaction, but variations in tensile strength could also arise from differences in void content, fiber alignment, or curing conditions. These results emphasize the importance of tailoring fiber combinations and controlling fabrication parameters to optimize composite performance. 3. Results and discussion 3.1. Tensile strength