scholarly journals A Feasibility Study for a Nonlinear Guided Wave Mixing Technique

2021 ◽  
Vol 11 (14) ◽  
pp. 6569
Author(s):  
Junpil Park ◽  
Jeongseok Choi ◽  
Jaesun Lee
Keyword(s):  
Effective Means ◽  
Guided Wave ◽  
Bulk Wave ◽  
Wave Mixing ◽  
Large Area ◽  
Destructive Testing ◽  
Main Research ◽  
System Nonlinearity ◽  
Nonlinear Technique ◽  
Equipment System

Ultrasonic non-destructive testing is an effective means of examining objects without destroying them. Among such testing, ultrasonic nonlinear evaluation is used to detect micro-damage, such as corrosion or plastic deformation. In terms of micro-damage evaluation, the data that comes from amplitude comparison in the frequency domain plays a significant role. Its technique and parameter are called ultrasonic nonlinear technique and nonlinearity. A certain portion of nonlinearity comes from the equipment system, while the other portion of nonlinearity comes from the material. The former is system nonlinearity, while the latter is material nonlinearity. System nonlinearity interferes with interpretation, because its source is not from the material. In this study, in order to minimize system effects, a mixing technique is implemented. To use the large area inspection ability of the guided wave, the main research issue in this paper is focused on the guided wave mixing technique. Moreover, several bulk wave mixing theory equations become good concepts for guided wave mixing theoretical study, and the conventional nonlinear technique and guided wave mixing experimental results are compared in this study to confirm the reliability. This technique can play an important role in quantitatively discriminating fine damage by minimizing the nonlinearity of the equipment system.

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.

scholarly journals Air-Coupled, Contact, and Immersion Ultrasonic Non-Destructive Testing: Comparison for Bonding Quality Evaluation

2020 ◽  
Vol 10 (19) ◽  
pp. 6757
Author(s):  
Bengisu Yilmaz ◽  
Aadhik Asokkumar ◽  
Elena Jasiūnienė ◽  
Rymantas Jonas Kažys
Keyword(s):  
Quality Evaluation ◽  
Lap Joints ◽  
Guided Wave ◽  
Bulk Wave ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Bonding Quality ◽  
Immersion Testing ◽  
Non Destructive ◽  
Ultrasonic Ndt

The objective of this study is to compare the performance of different ultrasonic non-destructive testing (NDT) techniques for bonding quality evaluation. Aluminium-epoxy-aluminium single lap joints containing debonding in the form of release film inclusions have been investigated using three types of ultrasonic NDT methods: contact testing, immersion testing, and air-coupled testing. Apart from the traditional bulk wave ultrasound, guided wave testing was also performed using air coupled and contact transducers for the excitation of guided waves. Guided wave propagation within adhesive bond was numerically simulated. A wide range of inspection frequencies causing different ultrasonic wavelengths has been investigated. Average errors in defect sizing per ultrasonic wavelength have been used as a feature to determine the performance of each ultrasonic NDT technique. The best performance is observed with bulk wave investigations. Particularly, the higher frequencies (10–50 MHz) in the immersion testing performed significantly better than air-coupled testing (300 kHz); however, air coupled investigations have other advantages as contactless inspection. Whereas guided wave inspections show relatively lower accuracy in defect sizing, they are good enough to detect the presence of the debonding and enable to inspect long range. Even though each technique has its advantages and limitations, guided wave techniques can be practical for the preliminary in-situ inspection of adhesively bonded specimens.

A Novel Defect Location Method for Plate-Like Structure by Using Forward-Scattering Wave and Fuzzy C-Means Clustering

2017 ◽  
Author(s):  
Shaojie Chen ◽  
Shaoping Zhou ◽  
Yong Li ◽  
Lanzhu Zhang
Keyword(s):  
Effective Means ◽  
Parallel Line ◽  
Forward Scattering ◽  
Guided Wave ◽  
Location Method ◽  
Operational Conditions ◽  
Fuzzy C Means ◽  
Defect Location ◽  
Scattering Wave ◽  
Fuzzy C Means Clustering

Ultrasonic guided wave technology combined with sparse transducer array provides an efficient and relatively cost-effective means of defect detection and monitoring for rapid interrogation of large in plate-like structures. However, imaging algorithm used baseline subtraction methods may be compromised under mismatched environment and operational conditions. A defect location method based on forward-scattering wave and fuzzy c-means clustering is proposed in this paper. The distance coefficient including location information between sensor pair using exciting and receiving signal and defect is defined to explain feasibility of the method proposed in this paper. A Parallel line array is evaluated using the method to locate defect. Experimental results show that the proposed method can effectively reduce the influence of mismatched environment and operational conditions on the defect location.

scholarly journals Detection of debonding in adhesive joints using Lamb wave propagation

2019 ◽  
Vol 262 ◽  
pp. 10012
Author(s):  
Magdalena Rucka ◽  
Erwin Wojtczak ◽  
Jacek Lachowicz
Keyword(s):  
Wave Propagation ◽  
Lamb Waves ◽  
Visual Assessment ◽  
Guided Wave ◽  
Steel Plates ◽  
Experimental Investigations ◽  
Mechanical Degradation ◽  
Adhesively Bonded ◽  
Destructive Testing ◽  
Out Of Plane

Adhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form of partial debonding) were prepared. The inspection was conducted with the use of guided wave propagation method. Lamb waves were excited at one point of the sample, whereas the out-of-plane velocity signals were recorded in a number of points spread over the area of overlap. The processing of signals consisted of calculations of weighted root mean square (WRMS). The results of the analysis showed that the WRMS maps allow for identification and determination of size and shape of debonding areas.

Comparison and Analysis of Effective Guided Wave Standards Between GB and ASTM

2019 ◽  
Author(s):  
Ju Ding ◽  
Min Zhang ◽  
Shu-hong Liu ◽  
Chen-huai Tang ◽  
Xu-chen Zhu ◽  
...  
Keyword(s):  
Thermal Power ◽  
Guided Wave ◽  
Test Method ◽  
Amplitude Curve ◽  
Non Destructive Testing ◽  
Ultrasound Guided ◽  
Destructive Testing ◽  
Wave Detection ◽  
Ultrasonic Guided Wave ◽  
Non Destructive

Abstract This paper discusses four different ultrasonic guided wave standards. Three of them are China’s national standards or industry standards: GB/T 31211-2014 “Nondestructive Testing Ultrasound Guided Wave Detection”, GB/T 28704-2012“Non-destructive testing—Test method for ultrasonic guided wave testing based on magnetostrictive effects”, and DL/T 1452-2015 “Thermal Power Pipeline Ultrasound Guided Wave Detection”. The another one is ASTM E2929:“Standard Practice for Guided Wave Testing of Above Ground Steel Piping with Magnetostrictive Transfusion”. Through six aspects in this article, including testing application scope, preliminary requirements, standard specimen and comparative specimen, distant amplitude curve and time gain curve, the existing difference between China and America is obvious and diversity. It is necessary to explore the underlying reasons for the connection of Chinese code and international code in the field of Non-destructive testing. During the standardization, anyone of the standard should be actually compared on the presentation of chart, and the verification and comparison of results, and lists the similarities and differences of each part based on GB31211. This paper provides reference for China to integrate with foreign standards in the field of ultrasonic guided wave detection of pressure vessel and pipelines.

Slow Lamb Wave Generation and Reception With a Gold-on-PVDF Interdigitated PVDF Transducer

2004 ◽  
Author(s):  
George M. Lloyd ◽  
Gu Hua ◽  
Ming L. Wang
Keyword(s):  
Lamb Wave ◽  
Single Mode ◽  
Wave Dispersion ◽  
Guided Wave ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Piezoelectric Polymers ◽  
Monitoring Applications ◽  
Signal Processing Algorithms ◽  
Non Destructive

Interdigitated surface and guided-wave transducers have only recently received attention as possible tools for non-destructive testing. This may be due in part to the increasing attention being paid to piezoelectric polymers as practical transduction materials for structural sensing and actuation. However, much remains to be done to produce a rugged, monolithic device oriented toward these sorts of applications, to characterize and optimize its passive and active response, to develop excitation strategies and signal processing algorithms that in tandem can be employed for arrayed structure monitoring applications. In this paper we confine ourselves to the first two topics and report on the development and proof-of-principle testing of a monolithic interdigitated polyvinyldine fluoride (PVDF) transducer. Specifically, we report on the design and response of an interdigitated transducer with relatively large finger spacings. The finger spacing yield measureable responses in the asymptotically slow single-mode region of Lamb wave dispersion behavior for frequency-thickness products which may be useful for nondestructive testing of many mechanical and civil structural systems.

scholarly journals Detection of Defects Using Spatial Variances of Guided-Wave Modes in Testing of Pipes

2018 ◽  
Vol 8 (12) ◽  
pp. 2378 ◽  
Author(s):  
Houman Mahal ◽  
Kai Yang ◽  
Asoke Nandi
Keyword(s):  
Detection Algorithm ◽  
Guided Wave ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Cross Sectional ◽  
The Past ◽  
Time Domain Signal ◽  
Non Destructive ◽  
Noise Region ◽  
Detection Of Defects

In the past decade, guided-wave testing has attracted the attention of the non-destructive testing industry for pipeline inspections. This technology enables the long-range assessment of pipelines’ integrity, which significantly reduces the expenditure of testing in terms of cost and time. Guided-wave testing collars consist of several linearly placed arrays of transducers around the circumference of the pipe, which are called rings, and can generate unidirectional axisymmetric elastic waves. The current propagation routine of the device generates a single time-domain signal by doing a phase-delayed summation of each array element. The segments where the energy of the signal is above the local noise region are reported as anomalies by the inspectors. Nonetheless, the main goal of guided-wave inspection is the detection of axisymmetric waves generated by the features within the pipes. In this paper, instead of processing a single signal obtained from the general propagation routine, we propose to process signals that are directly obtained from all of the array elements. We designed an axisymmetric wave detection algorithm, which is validated by laboratory trials on real-pipe data with two defects on different locations with varying cross-sectional area (CSA) sizes of 2% and 3% for the first defect, and 4% and 5% for the second defect. The results enabled the detection of defects with low signal-to-noise ratios (SNR), which were almost buried in the noise level. These results are reported with regard to the three different developed methods with varying excitation frequencies of 30 kHz, 34 kHz, and 37 kHz. The tests demonstrated the advantage of using the information received from all of the elements rather than a single signal.

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