Presentation Information
[21p-C501-11]Precise evaluation of pipe thickness by magnetic hammer testing using tunnel magneto-resistive sensors
〇(DC)Jun Ito1, Ryota Odagiri1, Shigetaka Suzuki1, Hiroshi Wagatsuma1, Kazuhiro Sugiyama1, Mikihiko Oogane1 (1.Tohoku univ.)
Keywords:
TMR sensor,Infrastructure inspection,Magnetic sensor
The rapid aging of water/oil pipes worldwide has become a significant social problem. Previous research has shown that it is possible to evaluate the aging of steel pipes based on their natural frequencies. We proposed a new nondestructive inspection method, the magnetic hammer test (MHT), using a tunnel magnetoresistive (TMR) sensor. Since TMR sensors can measure minute magnetic fields of sub-pT, they can detect minute magnetic fields generated by natural vibration of magnetic specimens with a high signal-to-noise ratio. In this study, several steel pipes with different thicknesses were measured to demonstrate the superiority of the MHT method. Pipes of different thicknesses were vibrated with a hammer, and the magnetic field oscillated by the vibration was observed with a TMR sensor. The experiment revealed that the natural frequency becomes lower as the amount of wall thinning increases. Based on these results, we attempted to inspect the pipe underwater using a waterproofed TMR sensor. In this presentation, we will analyze our experimental results in detail and discuss their potential for practical application.