Effect of damage on flexural modulus of C/C–SiC composites

The aim of the present work is to study the influence of damage in carbon–carbon silicon carbide composites (C/C–SiC) on their flexural resonant frequency as well as their flexural elastic modulus. Composite samples were examined by the grindosonic method and confocal laser scanning microscope before and after impact damage. Damage was introduced by the drop-weight (low-velocity) impact method using varying drop heights. The results show that the changes of the flexural resonant frequency after delamination/cracking of the matrix, compared to those of non-delaminated specimens, gave a good indication of the degree of damage, confirmed that the microcrack reduces the flexural resonant frequency and gave lower values of the modulus of elasticity.