PSI - Issue 52

Miray Yasar et al. / Procedia Structural Integrity 52 (2024) 165–175 Miray Yasar et. al. / Structural Integrity Procedia 00 (2019) 000 – 000

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with inadequate adhesion to the resin. Therefore, the study focused on P-PVDF CFRC. The typical R-curve (resistance curve) representing the G IC values over the delamination length of both composites is presented in Fig. 6. SEM images of the delaminated surface of the reference CFRC mode I fracture toughness sample (Fig. 7 a,b) indicate that the fibres separated easily from the matrix region during composite delamination. The delaminated surface of the P-PVDF CFRC displayed a neat region of Elium resin, with delamination occurring between the P PVDF layer and an adjacent layer of Elium resin. This resulted in minimum mechanical interlocking between fibre layers. As a result, CFRC composites showed better adhesion among the fibre and matrix compared to P-PVDF CFRC. One possible way of overcoming this issue is to treat the surface of the PVDF layer for better adhesion with the polymer resin or to place them away from the delamination layers. Figure 7 shows the mode I testing and delaminated layer of P-PVDF CFRC samples with the PVDF layer visible in the middle.

Fig. 6. SEM Images of the Mode I Fracture Toughness Samples (a, b) CFRC and (c, d) P-PVDF CFRC