Crack Propagation from a Circular Defect in a Unidirectional CFRP Composite under Dynamic Tension

Abstract

A single-ply unidirectional IM7/8552 carbon fiber reinforced plastic (CFRP) material with artificially introduced circular defects is subjected to dynamic tensile loading using a modified Kolsky tension bar. A high-speed X-ray phase contrast imaging method is integrated with the Kolsky bar setup to record the crack initiation from the defects and subsequent propagation in the material in real time during the tensile loading. The tensile loading was applied along the fiber direction (0°) of the specimens. Shear failure of the matrix and axial splitting along the loading/fiber direction (0°) were observed to initiate from the edge of the artificial circular defects. The dynamic tensile loading history during the crack propagation was recorded using a piezoelectric load cell.