PSI - Issue 77

João E. Ribeiro et al. / Procedia Structural Integrity 77 (2026) 300–307 J. Ribeiro et al./ Structural Integrity Procedia 00 (2026) 000–000

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3.2 Mechanical Characterization of Composite 3.2.1 Analysis of the Tensile Test Results

Three valid specimens were tested for each combination of parameters and levels described in Table 1 and the L₄ orthogonal array. Before testing, the width and thickness of each specimen were measured. Based on the tensile test data, the stress–strain curve was calculated and is presented in Figure 5.

Stress (MPa)

Strain

Fig. 5. Stress–strain curve obtained from the tensile test of composites.

Tensile strength averaged between 10 and 22 MPa, with a maximum of 28.08 MPa for the 3% treated-fiber composite, though this batch also showed the highest variability due to non-uniform plate quality. Maximum strain ranged from 0.83% to 1.65%, with the lowest value observed for the 6% untreated-fiber composite. 3.2.2 Analysis of the Flexural Test Results Five valid specimens were tested for each combination of parameters and levels described in Table 1 and the L₄ orthogonal array. Before testing, the width and thickness of each specimen were measured. Based on the flexural test data, the stress–strain curve was calculated and is presented in Figure 6.

Stress (MPa)

Strain

Fig. 6. Stress–strain curve obtained from the flexural test of the composites.