Complementary ex situ investigations of various fracture modes in a single-edge-notched symmetric cross-ply laminate subjected to tensile loading

Abstract

In situ experimentation using synchrotron radiation computed tomography (SRCT) is instrumental to observe subsurface mechanical behavior of composite materials in real time. However, the investigation areas of SRCT are often limited by its experimental configurations. In the present study, an ex situ observation is carried out to compliment the in situ test results reported previously in the literature. Previous SRCT-based in situ experiment on the single-edge-notched symmetric cross-ply laminate has visualized various failure modes at the notch, which are sequentially occurring inside the specimen. The tested specimen is further examined here using a laboratory-scale X-ray CT device with a dye penetrant. Delamination failures interacting with longitudinal and transverse cracks, which are not detected by the in situ test, are found with other failure modes distributed over the entire specimen area. The ex situ and in situ experimental results are complementary and both of them are required to comprehensively understand the various and complex failure mechanisms of the composites.