PSI - Issue 70

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

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Fig. 2. Tensile strength

3.2. Flexural Strength

Fig. 3. Flexural strength Fig. 3 illustrates the flexural strength of the composites. The flexural strength values of the samples, ranging from 52.58 MPa (Sample 1) to 67.72 MPa (Sample 4), indicate a progressive improvement in the ability of the composites to resist bending stresses, with Sample 4 showing the highest performance. The observed trend suggests that the combination of 40% banana fiber, 30% coir fiber, and 30% jute fiber in Sample 4 provides an optimal balance of reinforcement, resulting in enhanced load distribution and stiffness within the epoxy resin matrix. Conversely, Sample 1, with 50% banana and 50% coir fibers, exhibits the lowest flexural strength, likely due to weaker fiber synergy or suboptimal stress transfer. The slight decrease in flexural strength for Sample 5 (65.66 MPa), despite having a three fiber combination (33% banana, 33% coir, and 34% jute), might indicate less efficient bonding or higher void content compared to Sample 4. This variation highlights the influence of fiber proportions, alignment, and processing conditions on the bending performance of the composites. The consistent fiber volume fraction (60%) across all samples ensures uniform reinforcement, but the varying flexural strengths underline the critical role of fiber selection and distribution. These results emphasize the need to optimize fiber combinations and fabrication processes to achieve superior flexural performance.