PSI - Issue 78

Israel Sousa et al. / Procedia Structural Integrity 78 (2026) 1815–1822

1821

Fig. 7. Crack representation obtained using the DIC system. Figure 8a shows the response of the reference LBM sample, with a progressive decrease in the electrical conductivity as the damage index (dt) increases, indicating a correlation between mechanical and electrical behavior. However, the absence of a sharp electrical drop hinders the precise identification of crack initiation. From Figure 8b, although the electrical parameter initially drops sharply with increasing dt, indicating crack formation, it later exhibits alternating increases and decreases. This fluctuating behavior is likely associated with the bridging effect of carbon fibers, which temporarily restore electrical pathways across microcracks. For the CNT-doped sample (Figure 8c), the electrical signal exhibits minimal variation throughout the test, even at high damage levels (dt > 0.8), indicating limited crack sensitivity and, therefore, reduced potential for reliable damage detection. a) b)

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Fig. 8. Electrical parameter and of the (a) reference LBM sample; (b) LBM sample doped with 0.5% CCMF; and (c) LBM sample doped with 1.0% CNT.