Currently

the nondestructive testing and evaluation (NDT E) of R-zone in carbon fiber-reinforced composite structures (CFRCS) has become a focus in the area. A high-resolution ultrasonic technique was employed for the NDT E of T-shape R-zone in CFRCS based on the reflected echo signals and their characterizations by studying the interaction of incident short-pulse ultrasonic wave with T-shape R-zone. Series of ultrasonic testing and destructive testing experiments were carried out. A water-film couple method was used between transducer and T-shape R-zone surface. The incident direction and position of wave beam can be changed through the scanning of transducer and its aided mechanical device for 100% NDT of T-shape R-zone. Series of experimental and practical results have shown that the ultrasonic tech-nique is very powerful in the NDT E of T-shape R-zone in CFRCS. Defects and their exact positions in layup direction can be effectively discriminated and quantitatively determined according to the time-resolved reflected echoes from T-shape R-zone laminates and their time-domain characterization. The surface resolution and dead-zone of the ultrasonic method can be reached to 0.13mm

i.e.

the thickness of a single prepreg ply approximately. The series of destructive testing results have excellently demonstrated the correction of ultrasonic results compared with the real defect induced during the manufacturing of the CFRCS with T-shape R-zones.