Influence of voids on interlaminar shear strength of carbon/epoxy fabric laminates

The effects of voids (void content, void shape and size) on the interlaminar shear strength of [(±45)4/(0,90)/(±45)2]S and [(±45)/04/(0,90)/02]S composite laminates were investigated. Specimens with void contents in the range of 0.2%–8.0% for [(±45)4/(0,90)/(±45)2]S and 0.2%–6.1% for [(±45)/04/(0,90)/02]S were fabricated from carbon/epoxy fabric through varying autoclave pressures. The characteristics of the voids were studied by using optical image analysis to explain the interlaminar shear strength results. The influences of voids on the interlaminar shear strength of the two stacking sequences were compared in terms of the void content and size and shape of the void. The effect of voids on the initiation and propagation of interlaminar failure of both stacking sequence composites was found.