Fiber orientation study using ultrasonic C-scan of ply interfaces

A new method for direct mapping of ply orientations in composite laminates is presented. The method employs normal incidence ultrasound to scan ply interfaces and produce C-scan images that contain primarily the fiber orientation information of local plies. With the aid of two-dimensional Fourier transform, interface C-scan images were converted into angular distribution plots, which were then used to infer the orientation of individual plies. The method was tested on several different composite laminates and the interaction mechanisms were investigated.