The effect of mode II fatigue crack growth rate on the fractographic features of CFRP composite laminates: An acoustic emission and scanning electron microscopy analysis

The present study is focused on the characterization of fatigue damage features in carbon/epoxy laminates under mode-II loading conditions. To this aim, a sinusoidal cyclic load was applied to End-Notched Flexural (ENF) specimens and behavior investigated. Scanning Electron Microscope (SEM) used identify fracture surface, i.e. fiber imprints, cusps, roller striations. It found that features, such as cusps striations, completely depended crack growth rate, da/dN. In addition, linear relationship between striation space strain energy release rate range (ΔGs) hysteresis loop area established. Acoustic Emission (AE) method also employed characterize features. obtained results showed higher AE indicates larger rougher