Abstract
By a grazing SH-wave acoustoelasticity method, we tried to separate the stress anisotropy and the material anisotropy of structural material and to measure the residual stress of it. It was however difficult to measure with high accuracy in acoustoelasticity measurements by the grazing SH-wave because the measurements are strongly affected by coupling medium and the roughness of the surface of the material. In this study, we have developed a new-type grazing SH-wave transducer in order to suppress those influences. The transducer consisted of two transmitters and four receivers. The performance of the new transducer was compared with an earlier grazing SH-wave transducer by measuring the wave velocity of a rolled mild steel plate using a sing-around unit. Wave velocity measured by the new transducer was not influenced by change in couplant thickness with the passage of time, and was almost constant. We have measured the change in stress of the steel plate in the accuracy of ±5 MPa by using the new transducer. It has been demonstrated that the new transducer would be useful for measurement of the residual stress in the surface region of materials.
