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论文类型：期刊论文

发表时间：2015-03-01

发表刊物：ULTRASONICS

收录刊物：SCIE、EI、PubMed

卷号：57

期号：C

页面范围：190-197

ISSN号：0041-624X

关键字：Pipe inspection; Ultrasonic guided waves; Dent; Deformation rate

摘要：Guided elastic waves have been anticipated as a rapid screening technique for pipe inspection. Dents occurring in pipes are a severe problem which may lead to the possibility of pipe failure. A study of the reflection characteristics of guided waves from dents of varying geometrical profile in pipes is investigated through experiments. Dented region is represented by a series of circumferential cross-sections and its geometric parameters are described by axial length and the maximum and minimum outer diameters. Both single and double sided dents are mechanically simulated in hollow aluminum pipes and then experimentally tested by exciting the longitudinal L(0,2) mode. A quantitative parameter, so-called deformation rate relating to the maximum and minimum outer diameters of the dents is defined to evaluate the effect of the extent of the deformation on the reflection. For both types of dents, it is shown that the reflection coefficients of the L(0,2) mode are all approximately a linear function of their respective deformation rates. Mode conversion occurs at the dents and reflections of the F(1,3) mode are identified. The results show that the amplitude of the reflected F(1,3) mode is generally higher when the dent has stronger non-axisymmetric features. (C) 2014 Elsevier B.V. All rights reserved.