Progress and development trends of composite structure evaluation using noncontact nondestructive testing techniques in aviation and aerospace industries

Advanced composites are widely used in aviation and aerospace industries, some even replace metal as core parts of main structural material. Due to their special features in structure, material behavior and inspection conditions, several more rigorous and more targeted requirements for nondestructive testing are proposed including couplant-free, high testing efficiency, high reliability, real-time, visualized and environmental friendly, etc. Noncontact nondestructive testing techniques are viewed as viable solutions to meet the above requirements, and a variety of noncontact testing techniques have been offering services for aerospace manufacturing and maintenance. According to the development trends of aviation and aerospace industries and new inspection requirements for advanced composites, several well-suited, highly relevant and promising noncontact nondestructive testing techniques including air-coupled ultrasonic testing technique, infrared thermography, laser ultrasonic testing technique, and speckle pattern interferometry are summarized from different perspectives including technical features, research progress and applications. Finally, the development trends of noncontact nondestructive testing techniques are overviewed via synthesizing the research status of techniques above to provide certain references for the research and applications of these techniques in related industries.