Interlaminar crack initiation and growth rate in a carbon-fibre epoxy composite under mode-I fatigue loading

In this paper, interlaminar crack initiation and propagation under mode-I loading of a composite material made of an epoxy matrix reinforced with unidirectional carbon fibres are experimentally assessed for different asymmetry ratios. In the experimental program, DCB specimens were tested and the number of cycles to failure necessary for the onset of crack growth was registered for the asymmetry ratios R = 0.2 and R = 0.5. The G–N curves under...