Crack closure in the fatigue delamination of composite multidirectional DCB laminates with large-scale fiber bridging

The stress ratio is commonly known to have an effect on the fatigue delamination growth (FDG) behavior of composite laminates. The crack closure phenomenon during delamination growth may change the value of stress ratio. Whether the stress ratio effect on the FDG behavior is resulted by the crack closure or not is investigated in this study and experimental evidences are presented in order to obtain a reliable conclusion. Using the quasi-static...