EMAT Generation of Horizontally Polarized Guided Shear Waves for Ultrasonic Pipe Inspection

1998 ◽  
Author(s):  
Julie Gauthier ◽  
Vasile Mustafa ◽  
Ahmad Chabbaz ◽  
D. Robert Hay
Keyword(s):  
Mode Selection ◽  
Single Mode ◽  
Guided Wave ◽  
Sh Wave ◽  
Sh Waves ◽  
Acoustic Transducers ◽  
Ultrasonic Guided Wave ◽  
Cylindrical Steel ◽  
Pulse Echo ◽  
Multi Mode

In this work, an ultrasonic guided wave inspection technique was evaluated to detect and locate defects in pipes using SH (Horizontally polarized Shear) plate waves. Electromagnetic Acoustic Transducers (EMATs) were designed and constructed for bi-mode SH waves applications. These probes were used to generate a single mode at a time. Advantages of SH waves, guided by the wall surfaces for circumferential propagation and full volume inspection, are demonstrated in the pulse-echo setup. Mode selection criteria were investigated to tune the SH waves to the geometry of the inspection specimen Examples of mode selection based on the interaction characteristics of SH wave modes with a defect are described. An application of multi-mode inspection for geometrical parameter evaluation (length, depth and orientation) of individual cracks was also demonstrated. The experimental work was performed on cylindrical steel pipe samples having several types of defects ranging from through wall cracks to shallow cracks (10% of wall thickness) both in the circumferential and longitudinal directions. Results from laboratory investigation of the influence of defect depth and orientation on reflectivity of various modes of SH waves are reported. Multi-mode SH-wave inspection is shown to be capable of detecting shallow discontinuities (microcracks) and of locating defects accurately. Inspection results on a pipe section are represented as 3-D images with B-Scan projections and their interpretation is discussed.

scholarly journals Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning

2013 ◽  
Vol 113 (14) ◽  
pp. 144904 ◽  
Author(s):  
Pasi Karppinen ◽  
Ari Salmi ◽  
Petro Moilanen ◽  
Timo Karppinen ◽  
Zuomin Zhao ◽  
...  
Keyword(s):  
Laser Diode ◽  
Mode Selection ◽  
Wave Mode ◽  
Guided Wave ◽  
Diode Array ◽  
Laser Diode Array ◽  
Ultrasonic Guided Wave

Detection of Corrosion of Insulated Piping Using SH Angle Probe

2004 ◽  
Author(s):  
Tsutomu Kikuchi ◽  
Mitoshi Yotsutsuji ◽  
Yoshikazu Yokono ◽  
Kaoru Nitta ◽  
Yasushi Takagi
Keyword(s):  
Small Diameter ◽  
Longitudinal Direction ◽  
Guided Wave ◽  
Sh Wave ◽  
Sound Beam ◽  
Surface Corrosion ◽  
Ultrasonic Guided Wave ◽  
Internal Fluid ◽  
Potential Possibility ◽  
Wave Technique

One of the serious problems regarding insulated piping in petroleum and petrochemical plants is external surface corrosion. In general, visual inspection after removing insulation is carried out to detect corrosion. However, removing insulation is uneconomical, namely high cost, and time consuming processes are necessary such as setting up a scaffold. Ultrasonic guided wave technique has potential possibility to detect corrosion of long piping and has been recently investigated regarding its propagation characteristics. In this study, guided wave generated by horizontally polarized shear (SH) wave is applied to detect corrosion of insulated piping ranging from 1B to 3B. The reason why we select SH wave is that it has an advantage of being insensitive to internal fluid in piping. Through this study it is clear that SH guided wave is applicable to small diameter piping because sound beam of SH wave propagates along the longitudinal direction without circumferential extent. Accordingly local corrosion can be detected using SH guided wave technique.

Flaw Detection in Aluminum Plate by Shear Horizontal Guided Wave Based on Magnetostriction EMAT

2014 ◽  
Vol 614 ◽  
pp. 287-290
Author(s):  
Le Chen ◽  
Yue Min Wang ◽  
Hai Quan Geng
Keyword(s):  
Guided Waves ◽  
Flaw Detection ◽  
Test Sample ◽  
Guided Wave ◽  
Sh Waves ◽  
Electromagnetic Acoustic Transducers ◽  
Acoustic Transducers ◽  
Non Destructive ◽  
Viable Method ◽  
Shear Horizontal

Shear horizontal (SH) guided waves have been proved to be a viable method in the Non-Destructive Evaluation (NDE). Electromagnetic acoustic transducers (EMAT) can excite SH waves easily. By bonding the Fe-Co alloy to the test sample, the SH guided waves based on magnetostriction effect can be used to detect the flaw in nonferromagnetic material. The principle of exciting and receiving SH waves is introduced, and an experiment is carried out to validate the result.

Ultrasonic Circumferential Guided Wave for Pitting-Type Corrosion Imaging at Inaccessible Pipe-Support Locations

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. Shivaraj ◽  
Krishnan Balasubramaniam ◽  
C. V. Krishnamurthy ◽  
R. Wadhwan
Keyword(s):  
Guided Waves ◽  
Pipe Wall ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Structural Layout ◽  
Ultrasonic Guided Wave ◽  
Experimental Parameters ◽  
Data Acquisition Card ◽  
Pulse Echo

A higher order cylindrically guided ultrasonic wave was used for the detection and sizing of hidden pitting-type corrosion in the hidden crevice regions (between the pipe and the pipe supports) without lifting or disturbing the structural layout arrangement of the pipelines. The higher order circumferential guided waves were generated using a piezoelectric crystal based transducer, located at the accessible top region of the pipes, in a pulse-echo mode. By studying the experimental parameters such as dispersion, particle displacement, and wavelength of the ultrasonic guided wave modes, an appropriate higher order mode was selected for excitation using an appropriately designed acrylic angle wedge that conforms to the pipe’s outer curvature. A manual pipe crawler was designed with a provision for holding the wedge, and the essential hardware such as data acquisition card, encoder, etc., was integrated with the system so that the corrosion was mapped in real time during the scanning of the pipes. The system was validated on pipes ranging from 6in.to24in. outer diameters of wall thicknesses up to 12mm, by mapping defects as small as 1.5mm diameter and 25% penetration wall thickness. A 2D finite element model using ABAQUS® was used to understand the wave propagation in pipe wall and its interaction with pinhole-type defects.

scholarly journals Excitation efficiency analysis and mode selection on ultrasonic guided wave mixing

2019 ◽  
Author(s):  
Qian Wang ◽  
Wujun Zhu ◽  
Yanxun Xiang ◽  
Mingxi Deng ◽  
Fu-Zhen Xuan
Keyword(s):  
Mode Selection ◽  
Efficiency Analysis ◽  
Guided Wave ◽  
Wave Mixing ◽  
Excitation Efficiency ◽  
Ultrasonic Guided Wave

Numerical Investigation of Multi-Mode Guided Wave Focusing in Pipe–Like Structures Using Gradient Index Metamaterial Lens Design

2020 ◽  
Author(s):  
Hrishikesh G. Danawe ◽  
Didem Ozevin ◽  
Serife Tol
Keyword(s):  
Elastic Waves ◽  
Numerical Study ◽  
Guided Wave ◽  
Lens Design ◽  
Gradient Index ◽  
Focal Points ◽  
Theoretical Predictions ◽  
Multiple Frequencies ◽  
Cylindrical Steel ◽  
Multi Mode

Abstract This paper presents a numerical study on multi-mode focusing of guided elastic waves in pipe-like structures over a range of frequencies using a single metamaterial lens design. We explore focusing of the first two longitudinal (L(0,1) and L(0,2)) and the first torsional (T(0,1)) wave modes in steel pipe integrated with a metamaterial lens made of cylindrical steel stubs of varying heights attached to outer surface of the pipe. Proposed metamaterial lens design is based on gradient index (GRIN) theory with hyperbolic secant distribution of refractive index in circumferential direction. Amplification of multi-mode guided wave signals are achieved at focal points of the lens which is verified through numerical simulations. The focusing performance of proposed lens is studied at multiple frequencies for all the three modes and first two focal positions are verified with theoretical predictions of GRIN theory.

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