Study on Thickness and Actual Stress Measurement of Steel Structures Using Electromagnetic Acoustic Transducer

Abstract

Since an electromagnetic acoustic method could generate ultrasonic waves in the material surface non-contacting, high-precision wave velocity measurements were possible and application to steel structures is expected increasingly. On the other hand, from the aspect of the maintenance and control of steel structures, it is very important to measure quantitatively the wall-thinning and the actual stress of damaged and depleted materials by a non-destructive method. In this study, various examinations were performed to the wall-thinning measurement technique using an electromagnetic acoustic resonance method in which thickness and stress measurements are possible and the measurement method was established. Furthermore, as basic examination of actual stress measurements, a tensile testing was conducted by sensors of the shear wave and the longitudinal wave. As a result, it turned out that stress could be measured in a sufficient precision, and that the simultaneous measurement of thickness and stress became possible.