Scattering of the fundamental shear horizontal guided wave by a part-thickness crack in an isotropic plate

2008 ◽  
Vol 124 (5) ◽  
pp. 2895-2904 ◽  
Author(s):  
P. Rajagopal ◽  
M. J. S. Lowe
Keyword(s):  
Isotropic Plate ◽  
Guided Wave ◽  
Part Thickness ◽  
Shear Horizontal

SCATTERING OF THE FUNDAMENTAL SHEAR HORIZONTAL MODE BY PART-THICKNESS SURFACE-BREAKING CRACKS IN AN ISOTROPIC PLATE

2008 ◽  
Author(s):  
P. Rajagopal ◽  
M. J. S. Lowe ◽  
Donald O. Thompson ◽  
Dale E. Chimenti
Keyword(s):  
Isotropic Plate ◽  
Part Thickness ◽  
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 Point-Focusing Shear-Horizontal Guided Wave EMAT Optimization Method Using Orthogonal Test Theory

2020 ◽  
Vol 20 (12) ◽  
pp. 6295-6304 ◽  
Author(s):  
Hongyu Sun ◽  
Shen Wang ◽  
Songling Huang ◽  
Lisha Peng ◽  
Qing Wang ◽  
...  
Keyword(s):  
Optimization Method ◽  
Guided Wave ◽  
Orthogonal Test ◽  
Test Theory ◽  
Shear Horizontal

scholarly journals Characterization and Design Improvement of a Thickness-Shear Lead Zirconate Titanate Transducer for Low Frequency Ultrasonic Guided Wave Applications

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1848 ◽  
Author(s):  
Marco Zennaro ◽  
Dan J. O’Boy ◽  
Premesh Shehan Lowe ◽  
Tat-Hean Gan
Keyword(s):  
Lead Zirconate Titanate ◽  
State Of The Art ◽  
Guided Wave ◽  
Propagation Direction ◽  
Geometric Feature ◽  
Complex Signal ◽  
Current State ◽  
Out Of Plane ◽  
Shear Horizontal ◽  
Thickness Shear

Thickness-shear transducers for guided wave testing have been used in industry for over two decades and much research has been conducted to improve the resolution and sensitivity. Due to a geometric feature of the current state-of-the art transducer, there is an out-of-plane component in the propagation direction of the fundamental shear horizontal mode which complicates the signal interpretation. In such case, complex signal processing techniques need to be used for mode discrimination to assess the structural health with higher precision. Therefore, it is important to revise the transducer design to eliminate the out-of-plane components in the propagation direction of fundamental shear horizontal mode. This will enhance the mode purity of fundamental shear horizontal mode for its application in guided wave inspection. A numerical investigation has been conducted on a 3 mm thick 2 m circular steel plate to understand the behaviour and the characteristics of the state-of-the-art thickness-shear transducer. Based on the results, it is noted that the redesigning the electrode arrangement will suppress the out-of-plane components on the propagation direction of the fundamental shear horizontal mode. With the aid of this information current state-of-the-art transducers were redesigned and tested in laboratory conditions using the 3D Laser Doppler Vibrometer. This information will aid future transducer designers improve the resolution of thickness-shear transducers for guided wave applications and reduce the weight and cost of transducer array by eliminating the need of additional transducers to suppress spurious modes.

Scattering of a shear horizontal wave by a circular cavity in a piezoelectric bi-material strip based on guided wave theory

2020 ◽  
Vol 25 (4) ◽  
pp. 968-985 ◽  
Author(s):  
Hui Qi ◽  
Meng Xiang ◽  
Jing Guo
Keyword(s):  
Integral Equation ◽  
Electric Fields ◽  
Concentration Factor ◽  
Scattering Problem ◽  
Reference Value ◽  
Wave Theory ◽  
Guided Wave ◽  
Circular Cavity ◽  
Two Phase ◽  
Shear Horizontal

The scattering problem of a shear horizontal guided wave in a piezoelectric bi-material strip is analysed by means of the "mirror method," the Green’s function method and guided wave theory. A harmonic out-of-plane line-source force is applied at the junction of two-phase materials. Then, the bi-material strip is divided into two parts, and a pair of in-plane electric fields and a pair of counter-planar forces are applied to the vertical boundary. According to the boundary conditions, the Fredholm integral equation of the first kind is established by using the conjunction method. By effectively truncating the integral equation, the integral equation is simplified to an algebraic equation. The electric field intensity concentration factor and dynamic stress concentration factor around the circular cavity are obtained. The research content of this article is of great reference value in non-destructive testing, providing a reference for the judgement of the reliability of a piezoelectric bi-material strip.

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