2020 年 66A 巻 p. 540-548
For large-scale steel structures such as orthotropic steel decks in highway bridges, nondestructive inspection of fatigue damages is indispensable for securing their safety. The present authors developed a new thermography NDT technique for crack detection, which is based on temperature gap appeared on the surface of structural members due to thermal insulation effect of the crack. In this paper, the feasibility of the developed technique for detection of the non-penetrating fatigue cracks is investigated. The results of verification experiments using slit specimens and fatigue crack specimens are shown. The influence of anti-corrosion coating on the developed inspection is also clarified by FEM numerical simulation.