Sonic-IR法を用いたクレーン走行桁亀裂診断技術の開発

抄録

In recent study, active thermography has reached a high status as an easy and speedy defects inspection method in a NDT field. This paper newly proposes a remote and non-contact NDT method using a sonic-IR for detecting and evaluating of fatigue cracks at runway girder of the overhead crane in the steel making plant. In this method, fatigue cracks are detected as localized high temperature areas caused by friction and collision at crack surfaces with an infrared camera, applying a high-amplitude ultrasonic vibration. In this paper, sonic-IR method is applied to remote and high-efficient crack inspection of the runway girder in the overhead traveling crane. Target crack located in high place can be detected using this method without setting up scaffolding for inspection. And the threshold of vibration amplitude to generate the sufficient heat for crack detection is clarified. Therefore the system to prevent missing the crack by unsuccessful vibration transmission from vibrator is developed applying monitoring the vibration.Time and cost saving inspection method in runway girder of the overhead traveling crane is carried out using this NDT technique.