電磁超音波を用いた接着系アンカーの健全性評価に関する長谷部(OB)の論文が Acoustical Science and Technology に掲載されました。

Kazuhiko Hasebe, Yosuke Mizuno, Kentaro Nakamura. Non-contact alignment-free soundness evaluation of adhesive anchors by exciting/detecting longitudinal bolt vibrations using electromagnetic acoustic waves, Acoustical Science and Technology, vol. 38, no. 4, pp. 225-228, Jul. 2017.

Adhesive anchors are widely used in civil engineering applications, particularly to anchor the bolts of illuminators and ventilators in tunnels. The evaluation of the soundness of these anchors is essential to structural safety. In this work, based on this resonance-based technique, we implement a new electromagnetic acoustic transducer (EMAT)-based system for non-contact evaluation of the soundness of adhesive anchors, wherein we use the EMAT to both excite and detect longitudinal vibrations of bolts. This configuration does not require precise position alignment of the EMAT system, which will be of great use in practical applications. We investigate the influence of the amount and degradation of adhesive on the resonance frequency and the quality factor.