ガイド波用圧電式リング形センサーで励起した 円周Lambの共鳴現象を利用した肉厚測定法
Wall-thickness measurement by resonant phenomena of the circumferential Lamb waves generated and detected by eight transducer-elements located evenly on circumference of pipe.
著者:
森田 圭一 Keiichi MORITA 西野 秀郎 Hideo NISHINO
発刊日:
公開日:
Guided waveNondestructive evaluationPipeUltrasonic
概要
Piezoelectric ring-shaped sensor (PeRS) has been widely used for guided wave inspection of piping. The PeRS i s normally consisted of plural transducer elements located along circumference at regular interval. Due to th e structure, in addition to the axially propagating torsional mode guided waves, circumferential (C-) Lamb wa ves have also been generated as spurious waves at the same time. Especially in the resonant conditions determ ined by both the specific frequencies and locations of sensor elements, the C-Lamb waves are dominantly and p referentially generated as actual spurious signals that may distort axially propagating waves. In this paper, this troublesome phenomenon is used not for the axially propagating guided waves but usefully for the measur ements of wall thicknesses. The Principle, the verification and the accuracy of the measurements were shown.
