Issue 68

M. C. Chaves et alii, Frattura ed Integrità Strutturale, 68 (2024) 94-108; DOI: 10.3221/IGF-ESIS.68.06

Figure 15: Rupture of longitudinal fibers.

Furthermore, Fig. 16a illustrates the rupture of a bundle of transverse fibers, displaying a failure process characterized by the rupture of individual fibers known as singlets. A critical cluster of fiber breakage is formed as seen in Fig. 16b, eventually leading to material failure [43]. Again, surface defects inherent to the manufacturing process are visible.

(a)

(b)

Figure 16: Rupture of transversal fibers.

Fig. 17 illustrates the entire fracture surface in the testing area, revealing wear marks attributed to fatigue. The detachment of transverse fibers from the matrix is observed, indicating a variable strength of the fiber-matrix bond across the surface. The BioPoxy-Fique composite is estimated to have a fiber volumetric fraction (V f ) of 27%. In other studies, the fiber content in the composite has been found to influence its fatigue failure mechanisms under tension-tension loading. Studies have demonstrated that composites with a low fiber content exhibit a higher generation of surface cracks in the matrix during the early stages of fatigue [40].

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