This paper presents an innovative nondestructive evaluation (NDE) technology and development of the portable microwave equipment for composite structures including fiber reinforced polymer (FRP) wrapped concrete, focusing on the detection of debonding, void, and delaminations of FRP and concrete interface. The technology is based on the reconstruction of microwave signal profile on the scanned surface by sending toward and receiving back from the structure. Electrical material characters such as permittivity and loss factor were identified on several types of FRP and concrete, which serve as a foundation for determination of the system parameters and analysis of the performance. The microwave NDE equipment consists of array antennas as a microwave probe, signal source module, and a system controller. The system uses X-band microwave source for high-resolution and portability of the array antennas, which has high gain and narrow beamwidth. The system scans the surface of a structure by changing the focused point of microwave beam either mechanically or electronically. Experimental results on the several specimens showed the efficiency of the developed system.
展开▼
