Short range scattering of the fundamental shear horizontal guided wave mode normally incident at a through-thickness crack in an isotropic plate

2007 ◽  
Vol 122 (3) ◽  
pp. 1527-1538 ◽  
Author(s):  
P. Rajagopal ◽  
M. J. S. Lowe
Keyword(s):  
Short Range ◽  
Isotropic Plate ◽  
Wave Mode ◽  
Guided Wave ◽  
Shear Horizontal

Detection of Defects in Titanium Using Shear Horizontal Guided Waves

2021 ◽  
Author(s):  
Christian Peyton ◽  
Rachel S. Edwards ◽  
Steve Dixon ◽  
Ben Dutton ◽  
Wilson Vesga
Keyword(s):  
Guided Waves ◽  
Wave Mode ◽  
Guided Wave ◽  
Inspection System ◽  
Wave Direction ◽  
Finite Element Software ◽  
Small Defect ◽  
Back Face ◽  
The Relationship ◽  
Shear Horizontal

Abstract This paper investigates the interaction behaviour between the fundamental shear horizontal guided wave mode and small defects, in order to understand and develop an improved inspection system for titanium samples. In this work, an extensive range of defect sizes have been simulated using finite element software. The SH0 reflection from a defect has been shown previously to depend on its length as the total reflection consists of reflections from both the front and back face. However, for small defect widths, this work has found that the width also affects this interference, changing the length at which the reflection is largest. In addition, the paper looks at how the size of the defect affects the mode converted S0 reflection and SH0 diffraction. The relationship between the SH0 diffraction and defect size is shown to be more complex compared to the reflections. The mode converted S0 reflection occurs at an angle to the incident wave direction; therefore, the most suitable angle for the detection has been found. Simultaneous measurement of multiple waves would bring benefits to inspection.

scholarly journals Improved SH0 Guided Wave Transducers Based on Piezoelectric Fiber Patches

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2990 ◽  
Author(s):  
Kim ◽  
Gaul ◽  
Köhler
Keyword(s):  
Wave Mode ◽  
Guided Wave ◽  
Piezoelectric Transducers ◽  
Shear Horizontal Wave ◽  
Rounded Corner ◽  
Horizontal Wave ◽  
Transducer Design ◽  
Shear Horizontal ◽  
Transducer Type ◽  
Piezoelectric Fiber

A piezoelectric fiber patch (PFP) is a transducer type that is suitable for guided-wave-based structural health monitoring (SHM) due to its light, thin, and flexible characteristics. In our previous work, a PFP-based transducer design for selective excitation of the zero-order shear horizontal wave mode (SH0) was introduced (shear horizontal PFP (SHPFP)). In this work, two modified SH0 wave PFP transducer designs are proposed: the rounded corner design and the dual design. The degree of improvement is determined by a numerical simulation and the dual design—the design with the most promise—is experimentally realized. Laser Vibrometry measured the generated wave field, confirming the results from the simulation. The new designs can generate an almost pure SH0 wave. The dual design has a very strong directivity that is useful for several guided-wave-based SHM applications. The conclusions on the design’s properties as a transmitter are also valid for its properties as a sensor due to the reciprocity of piezoelectric transducers.

Phased annular array transducers for omnidirectional guided wave mode control in isotropic plate like structures

2013 ◽  
Vol 22 (12) ◽  
pp. 125022 ◽  
Author(s):  
Jaya P Koduru ◽  
Sepandarmaz Momeni ◽  
Joseph L Rose
Keyword(s):  
Isotropic Plate ◽  
Wave Mode ◽  
Guided Wave ◽  
Mode Control ◽  
Annular Array

scholarly journals High-resolution thickness maps of corrosion using SH1 guided wave tomography

2021 ◽  
Vol 477 (2245) ◽  
pp. 20200380
Author(s):  
Andreas A. E. Zimmermann ◽  
Peter Huthwaite ◽  
Brian Pavlakovic
Keyword(s):  
Petrochemical Industry ◽  
Guided Waves ◽  
Corrosion Damage ◽  
Wave Mode ◽  
Guided Wave ◽  
Resolution Limit ◽  
First Order ◽  
Wave Tomography ◽  
Plane Direction ◽  
Shear Horizontal

Quantifying corrosion damage is vital for the petrochemical industry, and guided wave tomography can provide thickness maps of such regions by transmitting guided waves through these areas and capturing the scattering information using arrays. The dispersive nature of the guided waves enables a reconstruction of wave velocity to be converted into thickness. However, existing approaches have been shown to be limited in in-plane resolution, significantly short of that required to accurately image a defect target of three times the wall thickness (i.e. 3 T) in each in-plane direction. This is largely due to the long wavelengths of the fundamental modes commonly used, being around 4 T for both A0 and S0 at the typical operation points. In this work, the suitability of the first-order shear-horizontal guided wave mode, SH1, has been investigated to improve the resolution limit. The wavelength at the desired operating point is significantly shorter, enabling an improvement in resolution of around 2.4 times. This is first verified by realistic finite-element simulations and then validated by experimental results, confirming the improved resolution limit can now allow defects of maximum extent 3T-by-3T to be reliably detected and sized, i.e. a long-pursued goal of guided wave tomography has been achieved.

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