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.

A Characteristic of Scattering Patterns from Defect in a Rail

2006 ◽  
Vol 321-323 ◽  
pp. 788-791
Author(s):  
Chong Myoung Lee ◽  
Joseph L. Rose ◽  
Youn Ho Cho
Keyword(s):  
Cross Section ◽  
Loading Condition ◽  
Guided Waves ◽  
Wave Structure ◽  
Propagation Characteristic ◽  
Guided Wave ◽  
Testing Methods ◽  
Wave Technique ◽  
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. The wave structure of the rail cross-section for a particular loading condition of modes and frequencies is an important feature. The wave structures are examined at different modes and frequencies. The propagation scattering patterns of guided waves from various multiple defects in a rail are also studied using finite element method.

Analysis on Characteristic Features of L-Mode Guided Wave in Tube Testing

2012 ◽  
Vol 710 ◽  
pp. 581-587
Author(s):  
S. Adalarasu
Keyword(s):  
Dispersion Characteristic ◽  
Wave Structure ◽  
Propagation Characteristic ◽  
Guided Wave ◽  
Chemical Plants ◽  
Steam Generators ◽  
Power Generators ◽  
Longitudinal Modes ◽  
Multiple Defect ◽  
Characteristic Features

Applications of long range ultrasonic testing are on cylindrical products(pipes and tubes) and planar products(plates and sheets).Guided wave testing using circumferential and longitudinal modes are getting more and more importance as there are huge requirements for testing pipes and tubes in power generators, Chemical plants, steam generators etc.. There will be infinite number of modes with charectestic propagation and wave structure. This propagation characteristic and wave structure plays a major role in deciding its suitability for use in specific application. It is highly essential to use mode control and to understand the generated modes and its characteristics based on which only testing adequacy can be evaluated. In this paper the characteristic features of L-mode generated using a source design parameter for tube testing are explained. The dispersion characteristic of L-mode are discussed using constructed Dispersion Curves, phase and group velocity, its multiple defect detection capability, pulse shape and amplitude dynamics with propagation range and inclination. The details of controlled experiment conducted and the observations are discussed. The derived inferences are explained based on the applicable particle displacement equations and dispersion characteristic equations.

Guided Wave Focusing Mechanics in Pipe

2003 ◽  
Author(s):  
Takahiro Hayashi ◽  
Koichiro Kawashima ◽  
Zongqi Sun ◽  
Joseph L. Rose
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Wave Structure ◽  
Guided Wave ◽  
Pipe Inspection ◽  
Specific Point ◽  
Wave Focusing ◽  
Beam Focusing ◽  
Subsequent Time

Guided waves can be used in pipe inspection over long distances. Presented in this paper is a beam focusing technique to improve the S/N ratio of the reflection from a tiny defect. Focusing is accomplished by using non-axisymmetric waveforms and subsequent time delayed superposition at a specific point in a pipe. A semi-analytical finite element method is used to present wave structure in the pipe. Focusing potential is also studied with various modes and frequencies.

scholarly journals Numerical and Experimental Investigation of Guided Wave Propagation in a Multi-Wire Cable

2019 ◽  
Vol 9 (5) ◽  
pp. 1028 ◽  
Author(s):  
Pengfei Zhang ◽  
Zhifeng Tang ◽  
Fuzai Lv ◽  
Keji Yang
Keyword(s):  
Wave Energy ◽  
Guided Waves ◽  
Wave Structure ◽  
Excitation Power ◽  
Dispersion Analysis ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Mechanical Coupling ◽  
Guided Wave Propagation ◽  
Contact Acoustic Nonlinearity

Ultrasonic guided waves (UGWs) have attracted attention in the nondestructive testing and structural health monitoring (SHM) of multi-wire cables. They offer such advantages as a single measurement, wide coverage of the acoustic field, and long-range propagation ability. However, the mechanical coupling of multi-wire structures complicates the propagation behaviors of guided waves and signal interpretation. In this paper, UGW propagation in these waveguides is investigated theoretically, numerically, and experimentally from the perspective of dispersion and wave structure, contact acoustic nonlinearity (CAN), and wave energy transfer. Although the performance of all possible propagating wave modes in a multi-wire cable at different frequencies could be obtained by dispersion analysis, it is ineffective to analyze the frequency behaviors of the wave signals of a certain mode, which could be analyzed using the CAN effect. The CAN phenomenon of two mechanically coupled wires in contact was observed, which was demonstrated by numerical guided wave simulation and experiments. Additionally, the measured guided wave energy of wires located in different layers of an aluminum conductor steel-reinforced cable accords with the theoretical prediction. The model of wave energy distribution in different layers of a cable also could be used to optimize the excitation power of transducers and determine the effective monitoring range of SHM.

Guided Wave Focusing Mechanics in Pipe

2005 ◽  
Vol 127 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Takahiro Hayashi ◽  
Koichiro Kawashima ◽  
Zongqi Sun ◽  
Joseph L. Rose
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Wave Structure ◽  
Guided Wave ◽  
Pipe Inspection ◽  
Specific Point ◽  
Wave Focusing ◽  
Beam Focusing ◽  
Subsequent Time

Guided waves can be used in pipe inspection over long distances. Presented in this paper is a beam focusing technique to improve the S∕N ratio of the reflection from a tiny defect. Focusing is accomplished by using nonaxisymmetric waveforms and subsequent time delayed superposition at a specific point in a pipe. A semianalytical finite element method is used to present wave structure in the pipe. Focusing potential is also studied with various modes and frequencies.

A Non-Contact Guided Wave Technique for Defect Thinning Monitoring

2006 ◽  
Vol 326-328 ◽  
pp. 681-684 ◽  
Author(s):  
Ik Keun Park ◽  
Yong Kwon Kim ◽  
Tae Hyung Kim ◽  
Yong Sang Cho
Keyword(s):  
Guided Waves ◽  
Guided Wave ◽  
Velocity Change ◽  
Accelerated Corrosion ◽  
Ultrasonic Guided Wave ◽  
Acoustic Transducer ◽  
Thin Aluminum ◽  
Wave Technique ◽  
Electro Magnetic ◽  
Flow Accelerated Corrosion

This paper capitalizes on recent advances in the area of non-contact ultrasonic guided wave techniques. The present technique provides a decent method for nondestructive testing of defect thinning simulating a hidden corrosion or FAC(Flow Accelerated Corrosion) in a thin aluminum plate. The proposed approach is based on using EMAT(Electro-magnetic Acoustic Transducer) to generate guided waves and detect the wall thinning without any coupling. Interesting features in the dispersive behavior of selected guided modes are used for the detection of plate thinning. It is shown that mode cut-off measurement allows us to monitor a defect thinning level while a group velocity change can be used to quantify the thinning depth.

scholarly journals Comparison of Ultrasonic Non-Contact Air-Coupled Techniques for Characterization of Impact-Type Defects in Pultruded GFRP Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1058
Author(s):  
Aadhik Asokkumar ◽  
Elena Jasiūnienė ◽  
Renaldas Raišutis ◽  
Rymantas Jonas Kažys
Keyword(s):  
Guided Waves ◽  
Lamb Waves ◽  
Tomographic Reconstruction ◽  
Guided Wave ◽  
Reconstruction Technique ◽  
Bulk Wave ◽  
Glass Fiber Reinforced Plastic ◽  
Ultrasonic Guided Wave ◽  
Single Side ◽  
Numerical Finite Element

This article compares different air-coupled ultrasonic testing methods to characterize impact-type defects in a pultruded quasi-isotropic glass fiber-reinforced plastic (GFRP) composite plate. Using the air-coupled transducers, comparisons among three methods were performed, namely, bulk-wave through transmission, single-side access using guided waves, and ultrasonic-guided wave tomography. The air coupled through transmission technique can determine the size and shape of impact-type defects with a higher resolution, but with the consequence of time consumption and, more importantly, the necessity of access to both sides of the sample. The guided wave technique on the other hand, allows a single-side inspection and is relatively fast. It can be used to determine the size of the defect using ultrasonic B-scan, but the exact shape of the defect will be compromised. Thus, in this article, to determine the shape of the defect, application of the parallel beam tomographic reconstruction technique using guided Lamb waves is demonstrated. Furthermore, a numerical finite element simulation was performed to study the effects of guided wave propagation in the composite sample and interaction with the internal defect. Lastly, the results from the experiments of different techniques were compared according to possibilities of defect sizing and determination of its shape.

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.

Propagation characteristics of ultrasonic guided waves in continuously welded rail

2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740075 ◽  
Author(s):  
Wenqing Yao ◽  
Fuwei Sheng ◽  
Xiaoyuan Wei ◽  
Lei Zhang ◽  
Yuan Yang
Keyword(s):  
High Speed ◽  
Guided Waves ◽  
Wave Structure ◽  
Dispersion Analysis ◽  
Ultrasonic Guided Waves ◽  
Bulk Wave ◽  
Propagation Characteristics ◽  
Destructive Testing ◽  
Continuously Welded Rail ◽  
Vibration Modal

Rail defects cause numerous railway accidents. Trains are derailed and serious consequences often occur. Compared to traditional bulk wave testing, ultrasonic guided waves (UGWs) can provide larger monitoring ranges and complete coverage of the waveguide cross-section. These advantages are of significant importance for the non-destructive testing (NDT) of the continuously welded rail, and the technique is therefore widely used in high-speed railways. UGWs in continuous welded rail (CWR) and their propagation characteristics have been discussed in this paper. Finite element methods (FEMs) were used to accomplish a vibration modal analysis, which is extended by a subsequent dispersion analysis. Wave structure features were illustrated by displacement profiles. It was concluded that guided waves have the ability to detect defects in the rail via choice of proper mode and frequency. Additionally, thermal conduction that is caused by temperature variation in the rail is added into modeling and simulation. The results indicated that unbalanced thermal distribution may lead to the attenuation of UGWs in the rail.

A flexural mode guided wave transducer for pipes based on magnetostrictive effect

2020 ◽  
Vol 64 (1-4) ◽  
pp. 335-342
Author(s):  
Yun Sun ◽  
Jiang Xu ◽  
Chaoyue Hu ◽  
Guang Chen ◽  
Yunfei Li
Keyword(s):  
Magnetic Field ◽  
Guided Waves ◽  
Permanent Magnets ◽  
Wave Structure ◽  
Guided Wave ◽  
Circumferential Direction ◽  
Bias Magnetic Field ◽  
Flexural Mode ◽  
Axial Crack ◽  
Wave Transducer

The flexural mode guided waves of pipes which are sensitive the axial crack and suitable for wave focused gain more attention recently. In this paper, a non-contact flexural mode guided wave transducer based on magnetostrictive effect is provided for pipes. Based on the magnetostrictive transduction principle and the wave structure of the flexural mode guided wave, the sensing method for generating and receiving the flexural mode guided waves based on magnetostrictive effect is obtained. According to the theoretical analysis, a non-contact magnetostrictive transducer for F (3, m) mode guided waves is given. Six permanent magnets which are evenly distributed in the circumferential direction of the pipe and arranged in opposite polarities are employed to provide the bias magnetic field in the circumferential direction. A solenoid coil is employed to induce the axial alternating magnetic field. The bias magnetic field distribution of the flexural mode guided wave in the pipeline is analyzed by the finite element simulation. The mode of the transduction guided wave in the pipe is verified by experiments based on the dispersion curves.

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