scholarly journals Ultrasonic Methods

2021 ◽  
pp. 87-131
Author(s):  
Vykintas Samaitis ◽  
Elena Jasiūnienė ◽  
Pawel Packo ◽  
Damira Smagulova
Keyword(s):  
Long Range ◽  
Guided Waves ◽  
Structural Integrity ◽  
Ultrasonic Inspection ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Bulk Wave ◽  
Destructive Testing ◽  
Fibre Breakage ◽  
Ultrasonic Methods

AbstractUltrasonic inspection is a well recognized technique for non-destructive testing of aircraft components. It provides both local highly sensitive inspection in the vicinity of the sensor and long-range structural assessment by means of guided waves. In general, the properties of ultrasonic waves like velocity, attenuation and propagation characteristics such as reflection, transmission and scattering depend on composition and structural integrity of the material. Hence, ultrasonic inspection is commonly used as a primary tool for active inspection of aircraft components such as engine covers, wing skins and fuselages with the aim to detect, localise and describe delaminations, voids, fibre breakage and ply waviness. This chapter mainly focuses on long range guided wave structural health monitoring, as aircraft components require rapid evaluation of large components preferably in real time without the necessity for grouding of an aircraft. In few upcoming chapters advantages and shortcommings of bulk wave and guided wave ultrasonic inspection is presented, fundamentals of guided wave propagation and damage detection are reviewed, the reliability of guided wave SHM is discussed and some recent examples of guided wave applications to SHM of aerospace components are given.

Development of Guided Wave Ultrasonic Inspection Method for Thick Composite Structures

2014 ◽  
Vol 592-594 ◽  
pp. 153-157
Author(s):  
U. Saikrishna ◽  
K. Srinivas ◽  
Y.L.V.D. Prasad
Keyword(s):  
Composite Structures ◽  
Guided Waves ◽  
Ultrasonic Inspection ◽  
Digital Signal ◽  
Guided Wave ◽  
Test Surface ◽  
Destructive Testing ◽  
Inspection Method ◽  
High Attenuation ◽  
Labview Software

Ultrasonic Non-destructive testing is a well known technique for inspecting fiber reinforced composite structures however; its capability is severely limited by the high attenuation in thick and multi layer structures. Guided wave ultrasonic inspection has been reported to be useful tool for quantitative identification of composite structures. It takes advantage of tailoring / generating desired ultrasonic wave modes (Symmetric and anti-symmetric) for improved transmission through the composite structure. For this, guided waves have to be generated selectively by precisely placing transducer at an angle to the test surface. Automation of two axis fixture for transmission and reception of transducers have to be used for avoiding manual errors. The captured signals have to be processed in order to extract useful information from the received ultrasonic signals. The proposed project aims at developing automated guided wave inspection methods along with digital signal processing for generating dispersion curves for thick composited. Using test laminates with implanted defects, methodology for thick composite inspection with guided wave ultrasonic’s will be established. For this data will be captured and analyzed using Labview software.

scholarly journals Rail Diagnostics Based on Ultrasonic Guided Waves: An Overview

2021 ◽  
Vol 11 (3) ◽  
pp. 1071
Author(s):  
Davide Bombarda ◽  
Giorgio Matteo Vitetta ◽  
Giovanni Ferrante
Keyword(s):  
Guided Waves ◽  
Structural Integrity ◽  
Diagnostic Procedures ◽  
Guided Wave ◽  
Rolling Stock ◽  
Technical Literature ◽  
Track Maintenance ◽  
Rail Network ◽  
Ultrasonic Guided Wave ◽  
Maintenance And Inspection

Rail tracks undergo massive stresses that can affect their structural integrity and produce rail breakage. The last phenomenon represents a serious concern for railway management authorities, since it may cause derailments and, consequently, losses of rolling stock material and lives. Therefore, the activities of track maintenance and inspection are of paramount importance. In recent years, the use of various technologies for monitoring rails and the detection of their defects has been investigated; however, despite the important progresses in this field, substantial research efforts are still required to achieve higher scanning speeds and improve the reliability of diagnostic procedures. It is expected that, in the near future, an important role in track maintenance and inspection will be played by the ultrasonic guided wave technology. In this manuscript, its use in rail track monitoring is investigated in detail; moreover, both of the main strategies investigated in the technical literature are taken into consideration. The first strategy consists of the installation of the monitoring instrumentation on board a moving test vehicle that scans the track below while running. The second strategy, instead, is based on distributing the instrumentation throughout the entire rail network, so that continuous monitoring in quasi-real-time can be obtained. In our analysis of the proposed solutions, the prototypes and the employed methods are described.

scholarly journals Laser Ultrasound Inspection Based on Wavelet Transform and Data Clustering for Defect Estimation in Metallic Samples

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 573 ◽  
Author(s):  
Hossam Selim ◽  
Miguel Delgado Prieto ◽  
José Trull ◽  
Luis Romeral ◽  
Crina Cojocaru
Keyword(s):  
Wavelet Transform ◽  
Spatial Clustering ◽  
Clustering Algorithms ◽  
Ultrasonic Waves ◽  
Internal Defects ◽  
Destructive Testing ◽  
Arrival Times ◽  
Time Frequency ◽  
Ultrasonic Methods ◽  
Ultrasound Inspection

Laser-generated ultrasound is a modern non-destructive testing technique. It has been investigated over recent years as an alternative to classical ultrasonic methods, mainly in industrial maintenance and quality control procedures. In this study, the detection and reconstruction of internal defects in a metallic sample is performed by means of a time-frequency analysis of ultrasonic waves generated by a laser-induced thermal mechanism. In the proposed methodology, we used wavelet transform due to its multi-resolution time frequency characteristics. In order to isolate and estimate the corresponding time of flight of eventual ultrasonic echoes related to internal defects, a density-based spatial clustering was applied to the resulting time frequency maps. Using the laser scan beam’s position, the ultrasonic transducer’s location and the echoes’ arrival times were determined, the estimation of the defect’s position was carried out afterwards. Finally, clustering algorithms were applied to the resulting geometric solutions from the set of the laser scan points which was proposed to obtain a two-dimensional projection of the defect outline over the scan plane. The study demonstrates that the proposed method of wavelet transform ultrasonic imaging can be effectively applied to detect and size internal defects without any reference information, which represents a valuable outcome for various applications in the industry.

Feature-guided wave-based health monitoring of bent plates using fiber Bragg gratings

2016 ◽  
Vol 28 (9) ◽  
pp. 1211-1220 ◽  
Author(s):  
Pabitro Ray ◽  
Prabhu Rajagopal ◽  
Balaji Srinivasan ◽  
Krishnan Balasubramaniam
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Guided Waves ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Guided Wave ◽  
Destructive Testing ◽  
Plate Structures ◽  
Structural Health ◽  
Bent Plates

Harnessing of ultrasonic guided waves confined in local features such as bends and welds, known as feature-guided waves, has emerged as a promising technique for non-destructive testing and structural health monitoring of industrial and aerospace structures. This article introduces a fiber Bragg grating based technique which uses feature-guided waves to detect anomalies or defects in plate structures with transverse bends. We are able to obtain good consistency between simulation and experimental results, both in the case of defect-free bent plates and those with transverse defects. Such results establish fiber Bragg gratings as a viable alternative to conventional techniques for structural health monitoring of bent plates.

A Wall Thinning Detection and Quantification Based on Guided Wave Mode Conversion Features

2006 ◽  
Vol 321-323 ◽  
pp. 795-798 ◽  
Author(s):  
Youn Ho Cho ◽  
Won Deok Oh ◽  
Joon Hyun Lee
Keyword(s):  
Long Range ◽  
Guided Waves ◽  
Velocity Dispersion ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Wave Mode ◽  
Guided Wave ◽  
Wall Thinning ◽  
Theoretical Analyses ◽  
Data Calibration

This study presents a feasibility of using guided waves for a long-range inspection of pipe through investigation of mode conversion and scattering pattern from edge and wall-thinning in a steel pipe. Phase and group velocity dispersion curves for reference modes of pipes are illustrated for theoretical analyses. Predicted modes could be successfully generated by controlling frequency, receiver angle and wavelength. The dispersive characteristics of the modes from and edge wall-thinning are compared and analyzed respectively. The mode conversion characteristics are distinct depending on dispersive pattern of modes. Experimental feasibility study on the guided waves was carried out to explore wall thinning part in pipe for data calibration of a long range pipe monitoring by comb transducer and laser.

Cumulative Second Harmonic Generation of Ultrasonic Guided Waves Propagation in Tube-Like Structure

2016 ◽  
Vol 24 (03) ◽  
pp. 1650011 ◽  
Author(s):  
Weibin Li ◽  
Mingxi Deng ◽  
Younho Cho
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Polyvinylidene Fluoride ◽  
Guided Waves ◽  
Second Harmonic ◽  
Cumulative Effect ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Material Nonlinearity ◽  
Fundamental Wave

Second harmonic generation of ultrasonic waves propagating in unbounded media and plate-like structure has been vigorously studied for tracking material nonlinearity, however, second harmonic guided wave propagation in tube-like structures is rarely studied. Considering that second harmonics can provide sensitive information for structural health condition, this paper aims to study the second harmonic generation of guided waves in metallic tube-like structures with weakly nonlinearity. Perturbation method and modal analysis approach are used to analyze the acoustic field of second harmonic solutions. The conditions for generating second harmonics with cumulative effect are provided in present investigation. Flexible polyvinylidene fluoride comb transducers are used to measure fundamental wave modes and second harmonic ones. The work experimentally verifies that the second harmonics of guided waves in pipe have a cumulative effect with propagation distance. The proposed procedure of this work can be applied to detect material nonlinearity due to damage mechanism in tube-like structure.

Time Reversal Technique for Ultrasonic Guided Wave Inspection

2006 ◽  
Vol 321-323 ◽  
pp. 776-779
Author(s):  
Hak Joon Kim ◽  
Sung Jin Song ◽  
Jung Ho Seo ◽  
Jae Hee Kim ◽  
Heung Seop Eom
Keyword(s):  
Time Delay ◽  
Power Plant ◽  
Time Reversal ◽  
Nuclear Power ◽  
Guided Waves ◽  
Performance Enhancement ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Ultrasonic Guided Waves ◽  
Ultrasonic Guided Wave

For the long range inspection of structures in nuclear power plant using array transducers, it is necessary to focus waves on defects under interrogation. To take care of such a need, in this study we adopt a time reversal technique that is claimed to be very robust to focus ultrasonic waves on defects. Specifically, we calculate the appropriate time delay using the time reversal technique and re-generate ultrasonic guided waves that are focusing to an interrogated defect with the calculated time delay. In this paper, we describe the principle of the time reversal technique briefly and present the performance enhancement obtained by the time reversal techniques.

scholarly journals Toward Robotic Inspection of Dry Storage Casks for Spent Nuclear Fuel

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
C. J. Lissenden ◽  
S. Choi ◽  
H. Cho ◽  
A. Motta ◽  
K. Hartig ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Crack Detection ◽  
Guided Waves ◽  
Structural Integrity ◽  
Spent Nuclear Fuel ◽  
Guided Wave ◽  
Radiation Environment ◽  
Breakdown Spectroscopy ◽  
Dry Storage ◽  
Horizontal Wave

Extended dry storage of spent nuclear fuel makes it desirable to assess the structural integrity of the storage canisters. Stress corrosion cracking of the stainless steel canister is a potential degradation mode especially in marine environments. Sensing technologies are being developed with the aim of detecting the presence of chloride-bearing salts on the surface of the canister as well as whether cracks exist. Laser-induced breakdown spectroscopy (LIBS) methods for the detection of Chlorine are presented. In addition, ultrasonic-guided wave detection of crack-like notches oriented either parallel or perpendicular to the shear horizontal wave vector is demonstrated using the pulse-echo mode, which greatly simplifies the robotic delivery of the noncontact electromagnetic acoustic transducers (EMATs). Robotic delivery of both EMATs and the LIBS system is necessary due to the high temperature and radiation environment inside the cask where the measurements need to be made. Furthermore, the space to make the measurements is very constrained and maneuverability is confined by the geometry of the storage cask. In fact, a large portion of the canister surface is inaccessible due to the presence of guide channels on the inside of the cask's overpack, which is strong motivation for using guided waves for crack detection. Among the design requirements for the robotic system are to localize and track where sensor measurements are made to enable return to those locations, to avoid wedging or jamming of the robot, and to tolerate high temperatures and radiation levels.

A Computational Tool for Defect Analysis in Rail with Ultrasonic Guided Waves

2006 ◽  
Vol 321-323 ◽  
pp. 784-787
Author(s):  
Chong Myoung Lee ◽  
Joseph L. Rose ◽  
Wei Luo ◽  
Youn Ho Cho
Keyword(s):  
Guided Waves ◽  
Wave Structure ◽  
Propagation Characteristic ◽  
Guided Wave ◽  
Bulk Wave ◽  
Transverse Cracks ◽  
Wave Technique ◽  
Multiple Defect ◽  
Important Means ◽  
Nondestructive Testing Methods

Rail represents one of the most important means of transportation. Many nondestructive testing methods have been used to find defects in rail. The guided wave technique is the most efficient because of its long propagation characteristic along the rail. Potential for detecting transverse cracks exists whereas standard bulk wave technique could miss the cracks. The wave structure of the rail cross-section for a particular loading condition of modes and frequencies is an important feature. In this paper, the propagation and scattering patterns of guided waves in a rail are studied using finite element methods. The wave structures are also examined. Various multiple defect situations and rail boundary conditions can also be studied.

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