title: The reflection of guided waves from simple supports in pipes.
abstract: Successful ultrasonic guided wave detection of flaws at support locations relies on the ability to distinguish between the reflection produced by a simple support on an undamaged pipe and the reflection produced by pipe flaws. Consequently, it is essential to know how the reflections produced by simple supports behave; very little work has so far been reported on this subject. Through finite element simulations and experiments, this study develops a systematic understanding of how ultrasonic guided waves propagating along a pipe, in particular the T(0, 1) mode, interact with simple supports. It is shown that, unlike the T(0, 1) mode in a free pipe, the torsional mode in a supported region has a cut-off frequency, below which it will not propagate; below this frequency the T(0, 1) reflection coefficient is large, and it quickly reduces beyond the cut-off.
authors.affiliation: Department of Mechanical Engineering, Imperial College, Exhibition Road, London SW7 2AZ, United Kingdom. .galvagni08@imperial.ac.uk
authors.forename: Andrea
authors.initials: A
authors.lastname: Galvagni
authors.forename: Peter
authors.initials: P
authors.lastname: Cawley
mesh_terms: D000162:Acoustics; D016477:Artifacts; D002617:Chemical Industry; D003252:Construction Materials; D008962:Models, Theoretical; D010578:Petroleum; D014465:Ultrasonics / Q000379:methods*
chemical_list: D010578:Petroleum