Ultrasonic Imaging Evaluation of Impact Damages in Composite Laminates

Impact damage is kind of harmful defect for composite structural safety, which is easy induced during manufacturing and in-service. A high resolution pulse ultrasonic imaging technique based on the interaction of probe ultrasound with carbon fiber-reinforced composite laminate was employed to NDT&T of impact damage. A high quality impulse ultrasonic focal beam was used as probe ultrasound. Signals reflected from the composite laminate body were captured by data acquisition unit when focal transducer scanned composite specimen with impact damage. In the same time, ultrasonic scanning system recorded all the data of ultrasonic signals and transducer positions. B-scan and T-scan imaging based on the data were organized to investigate and evaluate impact damage in the composite specimen. Experimental results showed that the exact distribution, orientation, evolving and depth of impact damage were seen well in cross-section of the specimen by B-scan imaging. The destructive area, configuration and development of the impact damage in different depth of specimen lay-up were exhibited well by means of T-scan imaging.