Non-Destructive Inspection of Bonded Components Using Singular Value Decomposition of Time-Series Temperature Variation Data

In the weld bonding used in automobiles, inspecting the adhesive areas is important to achieve the desired increase in rigidity. Active infrared thermography using flash lamp heating was applied to a weld-bonded specimen. Temperature differences were observed on the measurement surface depending on the presence or absence of adhesive, enabling the detection of the bonded areas. Furthermore, singular value decomposition (SVD) was applied to obtain time-series temperature variation data. SVD emphasizes the boundaries of the adhesive areas, improving the accuracy of inspections of the adhesive application areas.