An application of induction heating for fast thermal nondestructive evaluation

Abstract

The application of induction heating as a selective heat source in a thermal nondestructive evaluation system is described. The conductive parts of the sample are heated with a scanning induction coil. Defects such as broken fibers or delaminations affect the heat flow in the sample and thus can be detected by monitoring the infrared radiation from the sample surface. In addition to thermal irregularities, the altered electrical characteristics of the flaws also contribute to the signal. Therefore, the detectability of the defects can be enhanced compared to that of defects investigated using the traditional nonselective heating methods. The functionality of the system is demonstrated with carbon fiber reinforced composites.