Experimental Evaluation of the Damage Growth Restraining in 90° Layer of Thin-ply CFRP Cross-ply Laminates

Abstract In this paper, a systematic and detailed observation was made of the crack extension behavior of thin 90° layers of cross-ply carbon fiber reinforced plastics (CFRP) laminates. The effect of ply thickness on the crack propagation mechanism was discussed with respect to the energy release rate of the intralaminar transverse crack, calculated using finite element analysis. In a laminate with a 40 μm-thick-ply, the crack gradually extended with increasing strain. Conversely, extreme crack extension was found at around 1.0% strain in a laminate with a standard thick ply. Based on the numerical analysis, the crack suppression effect is verified using a thin ply; the effect is apparently caused by a decrease in the energy release rate at the crack tip in the thin layer.