Abstract
Matrix cracking behavior in multiple plies of composite laminates was experimentally investigated using [0/θ2/90]s CFRP laminates with θ=30, 45 and 60. Detailed accumulation process of matrix cracks in each ply was observed within the static tension test program by X-ray transmission and CT scanning techniques. In the case of [0/602/90] s specimens, numerous 60-ply micro cracks were induced by 90-ply crack initiation, while 30-ply cracks in [0/302/90] s specimens appeared as cracks propagating in the fiber direction. In addition, the micro cracks in 60-ply rarely extended in the fiber direction even at high strain levels. Finally, discussions on the formation of micro cracks in θ-ply were provided in terms of energy release rates associated with θ-ply crack propagation including the influence of 90-ply cracks.
