Three-Dimensional Scattering of an Incident Plane Shear Horizontal Guided Wave by a Partly through-Thickness Hole in a Plate

2016 ◽  
Vol 33 (1) ◽  
pp. 014302 ◽  
Author(s):  
Wen-Fa Zhu ◽  
Hai-Yan Zhang ◽  
Jian Xu ◽  
Xiao-Dong Chai
Keyword(s):  
Three Dimensional ◽  
Guided Wave ◽  
Plane Shear ◽  
Incident Plane ◽  
Shear Horizontal

scholarly journals Acoustic Forward Model for Guided Wave Propagation and Scattering in a Pipe Bend

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 486
Author(s):  
Carlos-Omar Rasgado-Moreno ◽  
Marek Rist ◽  
Raul Land ◽  
Madis Ratassepp
Keyword(s):  
Wave Propagation ◽  
Three Dimensional ◽  
Scattered Wave ◽  
Rectangular Domain ◽  
Guided Wave ◽  
Forward Model ◽  
Pipe Bend ◽  
Focusing Effect ◽  
Main Challenge ◽  
Local Point

The sections of pipe bends are hot spots for wall thinning due to accelerated corrosion by fluid flow. Conventionally, the thickness of a bend wall is evaluated by local point-by-point ultrasonic measurement, which is slow and costly. Guided wave tomography is an attractive method that enables the monitoring of a whole bend area by processing the waves excited and received by transducer arrays. The main challenge associated with the tomography of the bend is the development of an appropriate forward model, which should simply and efficiently handle the wave propagation in a complex bend model. In this study, we developed a two-dimensional (2D) acoustic forward model to replace the complex three-dimensional (3D) bend domain with a rectangular domain that is made artificially anisotropic by using Thomsen parameters. Thomsen parameters allow the consideration of the directional dependence of the velocity of the wave in the model. Good agreement was found between predictions and experiments performed on a 220 mm diameter (d) pipe with 1.5d bend radius, including the wave-field focusing effect and the steering effect of scattered wave-fields from defects.

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

In-plane shear of nanoprepreg/nanostitched three-dimensional carbon/epoxy multiwalled carbon nanotubes composites

2019 ◽  
Vol 53 (24) ◽  
pp. 3413-3431 ◽  
Author(s):  
Kadir Bilisik ◽  
Nesrin Karaduman ◽  
Gulhan Erdogan ◽  
Erdal Sapanci ◽  
Sila Gungor
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Shear Fracture ◽  
Three Dimensional ◽  
Carbon Fabric ◽  
Multiwalled Carbon ◽  
Plane Shear ◽  
The Matrix ◽  
Delamination Area ◽  
Base Structure

The in-plane shear properties of nanostitched three-dimensional (3D) carbon/epoxy composites were investigated. Adding the stitching fiber or multiwalled carbon nanotubes or nanostitched fiber into carbon fabric preform slightly improved the shear strength and modulus of stitched and stitched nanocomposites. The in-plane shear fracture of the base and nanostructures was extensive delamination and tensile fiber failures in the sheared region. But, the stitched and stitched nanocomposites had angular deformation of the stitching yarns in the fiber scissoring areas, shear hackles in the matrix and successive fiber breakages in the interlayers. Probably, this mechanism prohibited extensive interlayer opening in the nanostitched composites. The results exhibited that introducing the stitching fiber (1.44%) and multiwalled carbon nanotubes (0.03125%) in the base structure enhanced its transverse fracture properties as a form of confined delamination area. Therefore, the damaged tolerance properties of the stitched nanocomposites were enhanced.

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.

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