Honeycomb Structure Detection Using Pulsed Thermography

Pulsed thermography is a nondestructive evaluation method, which has been qualitatively and quantitatively applied for different classes of materials to detect variety of defects. In this study, one-dimensional theoretical model of transient heat conduction under an instantaneous plane source is described for its application in the detection of honeycomb structures. Three kinds of honeycomb structures, including glass fiber-reinforced plastics (GFRP) honeycomb, carbon fiber-reinforced plastics (CFRP), and aluminum (Al) honeycombs, were used to demonstrate the detection ability, and the defects include most typical defects in honeycomb structures, such as disbonds, fluid ingress, and excessive adhesive. The image sequences were used for defect detection, and temperature decay analysis was helpful for the characterization of defect types.