Добірка наукової літератури з теми "Torsional guided wave"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Torsional guided wave".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Torsional guided wave"
1
Zhang, Yinghong, Bin Wang, Xiao Wei, and Zhenghua Qian. "A study on torsional guided wave EMAT array and its application in embedment depth inspection of guardrail post." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (December 10, 2020): 1065–72. http://dx.doi.org/10.3233/jae-209422.
Повний текст джерелаАнотація:
It is always a challenge to quickly and effectively inspect the embedment depth of highway guardrail posts. This paper focuses on an electromagnetic ultrasonic transducer (EMAT) array that can excites torsional mode (T-mode) guided waves and applies it to check the embedment depth of guardrail posts. First of all, we presented a torsional guided wave EMAT array that can be used to quickly inspect the embedment depth of guardrail posts. The working principle of the EMAT array was described in detail. Secondly, a torsional guided wave EMAT array composed of 12 racetrack coils and 24 permanent magnets was simulated to verify the excitation and propagation process of torsional guided wave in a post. Then, a method for detecting the embedment depth of a post using the travel time of a torsional guided wave in the post was put forward. Finally, an experimental system was set up to carry out embedment depth detection experiments on posts with different depths buried in soil and concrete. Experiments have verified the feasibility of using the torsional guided wave EMAT array to inspect the embedment depth of the guardrail post.
2
Sun, Zongqi, Li Zhang, and Joseph L. Rose. "Flexural Torsional Guided Wave Mechanics and Focusing in Pipe." Journal of Pressure Vessel Technology 127, no. 4 (February 14, 2005): 471–78. http://dx.doi.org/10.1115/1.2065587.
Повний текст джерелаАнотація:
Theoretical work on flexural torsional guided waves in pipe is presented along with angular profile experimental justification. Combined with previous work on flexural longitudinal modes and axisymmetric longitudinal and torsional modes, this work now forms a framework of nonaxisymmetric guided wave mechanics in pipe. Pipe inspection experiments are also carried out by flexural torsional wave focusing to demonstrate the advantages of the focusing technique.
3
Park, Ik Keun, Yong Kwon Kim, Won Joon Song, and Yong Sang Cho. "Application of Torsional Mode of Guided Waves to Long Range Pipe Inspection." Key Engineering Materials 326-328 (December 2006): 473–76. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.473.
Повний текст джерелаАнотація:
Conventional non-destructive techniques for inspection of weld in pipelines require significant test time and high cost. In order to overcome these drawbacks in conventional NDT techniques, various techniques using ultrasonic guided waves have been developed and applied to the pipeline inspection. Recently, a fast calculation technique for guided wave propagation using a semi-analytical finite element method (SAFEM), PIPE WAVE ver.1.0, has been developed by T. Takahiro et al [1]. In this paper, the calculation of torsional mode propagation in a pipe using PIPE WAVE ver. 1.0 is introduced as a preliminary study and the application of the torsional mode of ultrasonic guided waves to long range pipe inspection is presented.. The characteristics and setup of a long range guided wave inspection system and experimental results in pipes of various diameters are introduced. The experimental results in mock-up pipes with cluster type detects show that the limit of detectable wall thickness reduction with this guided wave system is 2~3% in the pipe cross section area and the wall thickness reduction of 5% in cross section area can be detected when actual detection level is used. Therefore, the applicability of the ultrasonic guided wave technique to long range pipeline inspection for wall thickness reduction is verified.
4
Nakhli Mahal, Houman, Kai Yang, and Asoke Nandi. "Defect Detection using Power Spectrum of Torsional Waves in Guided-Wave Inspection of Pipelines." Applied Sciences 9, no. 7 (April 6, 2019): 1449. http://dx.doi.org/10.3390/app9071449.
Повний текст джерелаАнотація:
Ultrasonic Guided-wave (UGW) testing of pipelines allows long-range assessment of pipe integrity from a single point of inspection. This technology uses a number of arrays of transducers separated by a distance from each other to generate a single axisymmetric (torsional) wave mode. The location of anomalies in the pipe is determined by inspectors using the received signal. Guided-waves are multimodal and dispersive. In practical tests, nonaxisymmetric waves are also received due to the nonideal testing conditions, such as presence of variable transfer function of transducers. These waves are considered as the main source of noise in the guided-wave inspection of pipelines. In this paper, we propose a method to exploit the differences in the power spectrum of the torsional wave and flexural waves, in order to detect the torsional wave, leading to the defect location. The method is based on a sliding moving window, where in each iteration the signals are normalised and their power spectra are calculated. Each power spectrum is compared with the previously known spectrum of excitation sequence. Five binary conditions are defined; all of these need to be met in order for a window to be marked as defect signal. This method is validated using a synthesised test case generated by a Finite Element Model (FEM) as well as real test data gathered from laboratory trials. In laboratory trials, three different pipes with defects sizes of 4%, 3% and 2% cross-sectional area (CSA) material loss were evaluated. In order to find the optimum frequency, the varying excitation frequency of 30 to 50 kHz (in steps of 2 kHz) were used. The results demonstrate the capability of this algorithm in detecting torsional waves with low signal-to-noise ratio (SNR) without requiring any change in the excitation sequence. This can help inspectors by validating the frequency response of the received sequence and give more confidence in the detection of defects in guided-wave testing of pipelines.
5
Herdovics, Balint, and Frederic Cegla. "Structural health monitoring using torsional guided wave electromagnetic acoustic transducers." Structural Health Monitoring 17, no. 1 (December 1, 2016): 24–38. http://dx.doi.org/10.1177/1475921716682688.
Повний текст джерелаАнотація:
Torsional guided wave inspection is widely used for pipeline inspection. Piezoelectric and magnetostrictive transducers are most commonly used to generate torsional guided waves. These types of transducers require bonding or mechanical contact to the pipe which can result in changes over time which are undesirable for structural health monitoring. This article presents a non-contact Lorentz force–based electromagnetic acoustic transducer for torsional guided wave monitoring of pipelines. First, the excitation mechanism of the transducer is simulated by analyzing the eddy current and the static magnetic field using the finite element method. An electromagnetic acoustic transducer transformer model is presented which describes the eddy current generation transfer function and the ultrasound excitation. Independently simulated eddy current and magnetic fields are used to calculate the Lorentz force that an electromagnetic acoustic transducer array induces on the surface of a 3-in schedule 40 pipe, and an explicit finite element solver is then used to simulate the elastic wave propagation in the pipe. Then, the reception mechanism and the expected received signal levels are discussed. The construction of an experimental transducer is described, and measurement results from the transducer setup are presented. The measured and modeled performance agree well. Finally, a monitoring example is presented where an artificial defect with 3% reflection coefficient is introduced and successfully detected with the designed sensor.
6
Cheong, Yong Moo, Shin Kim, and Hyun Kyu Jung. "Application of Magnetostrictive Transducer for the Long-Range Guided Wave Inspection." Key Engineering Materials 345-346 (August 2007): 1295–98. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.1295.
Повний текст джерелаАнотація:
The leakage of the pipes is a major issue for the safety of industrial structures. However, in many cases, because of their geometrical complexity and inaccessibility, it is difficult to inspect them by the conventional NDE method. A long-range guided wave inspection, thus, is an option to inspect them. A torsional vibration mode, T(0,1) shows many advantages in a long-range guided wave examination of a pipe, such as no dispersion characteristic, no radial displacement and low attenuation. However, it is not easy to fabricate a transducer with an array of piezoelectric elements for generation of torsional vibration mode and even expensive. Recently a magnetostrictive metal strip sensor was used for a generation of the torsional vibration modes in a pipe and this technique has shown several advantages for practical applications. This study investigated the applicability of a long-rang guided ultrasonic method to the detection of artificial notches even in the presence of various foreign objects.
7
Hu, Jian Hong, Zhi Feng Tang, and Fu Zai Lv. "The Analysis of Mechanism for Generating and Detecting Torsional Guided Wave." Applied Mechanics and Materials 401-403 (September 2013): 1162–65. http://dx.doi.org/10.4028/www.scientific.net/amm.401-403.1162.
Повний текст джерелаАнотація:
The T(0,1) mode guided wave is widely used in long term NDT of the pipelines. The magnetostrictive transducer for generating and detecting guided wave is important to long term NDT of the pipelines because the transducer is compact and can be used at high temperature. The paper explains the mechanism of the generation and detection of T(0,1) mode guided wave in magnetostrictive strip based on Wiedemann effect. The experiment with MSGW is done to confirm the mechanism in a aluminum pipe.
8
Quiroga Mendez, Jabid E., Octavio Andrés González-Estrada, and Yesid Rueda Ordonez. "Stress Sensitivity of the T(0,1) Mode Velocity for Cylindrical Waveguides." Key Engineering Materials 774 (August 2018): 453–60. http://dx.doi.org/10.4028/www.scientific.net/kem.774.453.
Повний текст джерелаАнотація:
In this paper, the stress influence in the guided wave velocity of the fundamentaltorsional mode is presented. Two analytical models, based on the Acoustoelasticity effect, tocompute the fundamental torsional mode velocity propagating in a specimen subject to anaxial stress are studied. These models are obtained due to the relation between the T(0, 1)guided wave velocity and the bulk shear velocity. The analytical models to calculate the guidedwave velocity are functions of the stress, second and third order elastic constants. A series ofaxial stress levels applied to a cylindrical waveguide is investigated with numerical simulations(Finite Elements) to estimate variations of the T(0, 1) guided wave velocity. This analysisprovides a criterion to evaluate the practical implementation of a stress monitoring schemebased on velocity variations of the fundamental torsional mode.
9
Fan, Zeng, Xudong Niu, Baichun Miao, and Hongying Meng. "Hybrid Coded Excitation of the Torsional Guided Wave Mode T(0,1) for Oil and Gas Pipeline Inspection." Applied Sciences 12, no. 2 (January 13, 2022): 777. http://dx.doi.org/10.3390/app12020777.
Повний текст джерелаАнотація:
Ultrasonic guided wave testing is an essential technique in non-destructive testing for structural integrity of oil and gas pipelines. This technique, based on the pulse-echo method, is often used for the long-range detection of pipelines at any location. However, guided waves suffer from high attenuation when they propagate in attenuative material structures and multiple wave modes due to the excitation, which reduces the power of echo signals and induces corruption caused by coherent noise. In this paper, a developed hybrid coded excitation method that uses the convolution of a Barker code and Golay code pair is proposed and applied for an ultrasonic guided wave testing system to excite the torsional guided wave mode T(0,1) in a steel pipe. The proposed method combines the advantages of these two coding methods and increases the flexibility of code lengths. The performance is evaluated by signal to noise ratio and peak sidelobe level of the processed signal. Both theoretical simulations and experiments have investigated using the proposed codes composed of Barker codes and Golay code pairs of different lengths and combinations. The experimental results show the significant improvement of the signal to noise ratio and the peak sidelobe level due to the proposed hybrid code usage for the excitation of guided waves. The values are further improved to around 32 dB and around −24 dB, respectively. Overall, the proposed hybrid coded method for improving the echo SNR can benefit from guided wave testing to reduce coherent and random noise levels and many other potential applications.
10
Kim, Young-Wann, and Kyung-Jo Park. "Characterization of Axial Defects in Pipeline Using Torsional Guided Wave." Transactions of the Korean Society for Noise and Vibration Engineering 25, no. 6 (June 20, 2015): 399–405. http://dx.doi.org/10.5050/ksnve.2015.25.6.399.
Повний текст джерелаДисертації з теми "Torsional guided wave"
1
Deere, Matthew. "Guided wave evaluation of pipes using the first and second order torsional wave mode." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/15307.
Повний текст джерелаАнотація:
Guided wave inspection is a form of ultrasonic testing used for non-destructive testing (NDT). Guided waves are capable of propagating long distances bounded by the geometries of the specimen, such as pipes and plates. The technique is commercially used to detect defects in pipelines and is capable of a full volumetric screening many metres (often up to around 100m) from one location. Fundamental axisymmetric wave modes are used to inspect pipelines and are used to quantify defects and features. However, as the technology has progressed, a demand for improving defect sensitivity, spatial resolution and developing the technology into new fields has been recognised. Operating at medium range frequencies is one possibility that could provide the increase in defect sensitivity and spatial resolution required that may not be achieved at low range frequencies. The use of higher order wave modes could also provide additional information useful for defect sizing. Guided wave inspection is a complex ultrasonic technique due to the many wave modes that exist and testing at medium range frequencies requires some challenges to be overcome. The research presented here investigates the potential of using the second order torsional wave mode at medium range frequencies and provides a new sizing technique that for some applications is likely to offer advancement in guided wave inspection and monitoring. The approach firstly included the design and implementation of a setup for analysing the complex signal responses in order to access the higher order torsional wave mode T(0,2) for defect sizing. An efficient method of using FEA has been presented using segmented models to provide the capability of analysing defects with small increment changes that could not be achieved using a full 3D model of the pipe. Using a pipe segment to virtually represent the full pipe also allowed small changes in defect size to be investigated, which would otherwise be extremely difficult to accurately machine experimentally. The FEA modelling technique is also based on broadband signals in comparison to the conventional approach of using narrowband signals and is capable of obtaining a wide frequency spectrum from one model, which significantly reduces the number of models needed to conduct a frequency analysis. Following on from this work, a high density transducer array was developed and compared against a conventional transducer array used in guided wave inspection for the purpose of medium range frequency inspection, which can also be applied to conventional low range frequency inspection. Finally, a new defect sizing method using T(0,2) is presented, which is capable of predicting the depth using peak amplitude responses from spectral analysis and by comparing this to the cut-off frequency of the remaining wall thickness of the defect. The technique has the potential to improve defect sizing, defect sensitivity, increase spatial resolution, and increase the performance of medium range inspection.
2
Carandente, Rosalba. "Interaction between the fundamental torsional guided wave mode and complex defects in pipes." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9484.
Повний текст джерелаАнотація:
The presence of defects in pipelines is a concern especially in petrochemical applications where the service integrity of pipes is a fundamental requirement to avoid process interruptions and to fulfil safety standards. Guided wave inspection is now routinely used in industry for screening long lengths of pipe for corrosion, any suspect areas then being followed up with conventional ultrasonic thickness gauging. However, this is difficult in cases where the suspect area is inaccessible (e.g. buried pipelines or pipes passing though walls), so it would be very useful to apply guided wave techniques for sizing as well as the detection and location of defects. This target is challenging due to the complexity of the profiles encountered in practice. The present work aims to improve the understanding of the scattering of the fundamental torsional mode T(0, 1) from complex shaped discontinuities and to determine the controlling parameters of this phenomenon. The overall analysis starts with a study of the reflection from axi-symmetric tapered steps and notches in pipes. After that the scattering from three dimensional (3D) defects with different shapes has been studied. Firstly, flat-bottomed defects with different surface profiles have been analyzed, and then the study of the reflection behavior from 3D defects with varying depth profile has been carried out. All of the work presented here uses the T(0,1) mode for inspection. It is revealed that the reflection coefficient maxima from axi-symmetric tapered defects decrease with increasing frequency as the slope of the taper becomes more gradual, this effect being more pronounced when the ratio of the average defect length to the wavelength increases. Tapered defects are therefore expected to be more difficult to detect at higher inspection frequencies; this effect is more evident for shallower tapers. It is also found that at a given maximum depth of a finite discontinuity, the peak of the reflection coefficient from a defect is linearly dependent on the circumferential extent of the defect, and is independent of its shape. The results from these analyses have been used to propose a practical approach to determine the maximum depth of a complex discontinuity from the reflection coefficient behavior, provided that the external circumferential extent of the defect is known. This method has been applied to real corrosion patches and the results validated with experiments. Its main limitation is on defects with a gradual corrosion section profile, but with a sudden change of the depth over a small circumferential region. It is shown then that a possible way to diagnose sharp circumferential profile changes is to measure the reflection coefficient spectrum at frequency higher than usually used in long range guided wave inspection.
3
Kharrat, Mohamed. "Design and development of a torsional guided-waves inspection system for the detection and sizing of defects in pipes." Thesis, Ecully, Ecole centrale de Lyon, 2012. http://www.theses.fr/2012ECDL0016/document.
Повний текст джерелаАнотація:
Plusieurs industries manipulent des substances liquides et gazeuses qui circulent souvent dans de longues canalisations. La technique d'ondes guidées est couramment utilisée dans ce domaine. Cette technique est en progrès continu. Dans cette thèse, un système d'inspection a été conçu et développé. Il est basé sur des transducteurs piézoélectriques qui génèrent des ondes guidées de torsion pouvant se propager le long du tube testé. Les signaux réfléchis des défauts et singularités rencontrés sont détectés aussi par des capteurs piézoélectriques. Des simulations numériques utilisantpar la méthode d'éléments finis standard et la méthode Wave Finite Element(WFEM) ont été effectuées afin de vérifier et de visualiser le phénomène de propagation des ondes dans des tubes intacts et endommagés. Un ensemble de tests a été mis en place sur des tubes droits et courbés avec deux matériaux différents: PVC et acier. L'interaction entre les ondes générées et les défauts usinés a été prouvée.Les résultats numériques et expérimentaux confirment certaines caractéristiques spécifiques concernant le coefficient de réflexion de l'onde. Par la suite, un pipeline industriel d'environ soixante mètres de long et contenant plusieurs défauts et singularités a été testé par le système d'inspection. Les signaux enregistrés ont soumis certains traitements numériques afin de les rendre exploitables. Les signaux traités sont analysés afin d'identifier et de distinguer les réflexions des défauts de celles des singularités structurés. La méthode WFEM a été employée pour construire une base de données numérique des coefficients de réflexion en variant la profondeur et les extensions axiale et circonférentielle du défaut modélisé. Le calcul a été établi en fonction de la fréquence. La corrélation des tailles des défauts est effectuée en balayant la base de données numérique pour trouver la combinaison appropriée de dimensions pour un défaut donné. Les réflexions à partir des singularités structurées (coudes, blocs de béton, colliers, et les soudures) sont traitées ainsi en comparant des coefficients de réflexion obtenus par WFEM à ceux évalués expérimentalement. Enfin, on a étudié numériquement l'effet de la position angulaire d'un défaut sur les coefficients de réflexion et de transmission tout en excitant à différents types d'ondes. La méthode WFE est aussi utilisée pour effectuer le calcul. Cette étude donne un guide à la localisation circonférentielle des défauts dans les tubesLong pipelines are widely used in several industries transporting liquid or gas. The guided wave technique is commonly used in this field and it is under continuing progress. In this thesis, an inspection system has been designed and developed. Piezoelectric transducers are employed to generate torsional guided waves that could propagate along the tested pipe; and receive reflected signals from encountered features and damages. Numerical simulations using standard FE and Wave Finite Element methods have been carried out in order to verify and visualize the wave propagation phenomenon in both intact and damaged pipes. A set of tests has been performed on straight and curved pipes with two different materials: PVC and steel. The interaction between generated waves and machined defects has been proven. Numerical and experimental results confirm some specific features in the wave reflection coefficient. Thereafter, an industrial pipeline of about sixty meters long and containing several features has been tested by the inspection system.Recorded signals had submitted some numerical treatments in order to make them interpretable. Processed signals are analyzed to identify defects reflections from structured singularities echoes. The Wave Finite Element Method (WFEM) has been used to construct a numerical database of reflection coefficients from modelled defects by varying thickness, axial and circumferential extents. Calculation was made depending on frequency. The approximation of defect sizes is carried out by sweeping the numerical database to find the suitable combination of dimensions fora given defect. Reflections from structural singularities (elbows, concrete blocks,clamps, and welds) are treated as well by comparing reflection coefficients obtained by WFEM to those evaluated experimentally. Finally, a numerical investigation deals with the effect of defect angular-position on reflection and transmission coefficients while exciting by different types of waves. The spectral method Wave Finite Element has been used to carry out calculation. This study gives guidance to circumferential localization of defects in pipes
4
Spratt, William. "Design and Testing of an Ultrasonic Torsional Wave Sensing Platform." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/SprattW2009.pdf.
Повний текст джерела
5
Li, Qingchun. "Measurement of acoustic properties of materials using torsional waves." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/15860.
Повний текст джерела
6
Yeung, Carman. "Investigation of Linear and Nonlinear Torsional Guided Waves in Hollow Circular Cylinders for Damage Detection." Thesis, 2021. http://hdl.handle.net/2440/130216.
Повний текст джерелаАнотація:
Non-destructive testing plays an important role in structural health monitoring. One of the promising options is the use of guided wave for damage detection in engineering applications, such as pipeline and truss system. Common types of damage in the structures include cracks and corrosion. Guided wave is sensitive to cracks up to micro scale. Long range inspection is the other benefit of using guided wave. The overall aim of this thesis is to present a systematic investigation of guided wave in pipe-like structures to gain physical insights into linear and nonlinear features associated with torsional guided wave interaction with damage.
This thesis includes a number of published and prepared journal papers under the same topic. The overview of linear and nonlinear guided wave, and guided wave mixing is introduced in Chapter 1. A computational model using one-dimensional time-domain spectral finite element with cracked element is presented in Chapter 2. This chapter mainly focuses on linear features of guided wave, such as scattering and mode conversion phenomena. The results show that the proposed cracked model has good agreement between the experimental results and three-dimensional (3D) finite element (FE) simulations.
Nonlinear guided wave is highly sensitive to early stage of micro cracks. Material nonlinearity is one of the nonlinear phenomena in the presence of the micro cracks. It can induce higher-order harmonics of guided wave. Guided wave mixing is the advanced version of nonlinear guided wave since the generation of combinational harmonics at sum and difference frequencies can minimise the effect due to the nonlinearity generated by equipment. Chapter 3 analyses the nonlinear characteristics of two interacting fundamental torsional guided wave modes numerically and experimentally. Chapter 4 and Chapter 5 are the extension parts based on the work in Chapter 3 since pipe-like structures are commonly used in many circumstances, for example embedded pipes and pre-stressed hollow structures. Comprehensive studies in this thesis can gain more understanding for the real applications. In Chapter 4, a 3D FE embedded pipe model with the implementation of nonlinear strain energy function is established to simulate the energy leakage of guided wave propagation due to the existence of soil media. The use of 3D laser scanning system receives guided wave signals from the surface of the pipe for verification. Both numerical and experimental results indicate a significant decline in the interested harmonics at mixed frequency and single frequency. On the other hand, acoustoelastic effect is studied in Chapter 5. A series of case studies are carried out to observe the group velocity change with respect to different levels of loading. The nonlinear features, such as combinational harmonics and second harmonics, are also investigated numerically and experimentally.Thesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 2020
7
Hsu, Wen-Chieh, and 許聞傑. "Focused Torsional Guided Wave for Defects Inspection on Elbow Using Time Reversal Method." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/796cdp.
Повний текст джерелаАнотація:
碩士國立中山大學
機械與機電工程學系研究所
103
Among the non-destructive testing techniques, guided waves has the characteristics of propagating long distance and being hard to attenuate, and it can also detect quickly and widely for the entire pipelines. However, identifying the signals of defects during the test is frequently difficult as a result of its multimodal and dispersive characteristics. Pipelines system is widespread use in petrochemical industry to transport gas or fluid. In virtue of restriction of space and pipelines planning, elbow parts will certainly provide to connect pipes, and this kind of complex pipe feature will bring about not only difficult to recognize signals but change direction of wave energy, that is, the energy will gather together outside of the elbow because of its geometry, then rest of the elbow will be blind area for the testing. In order to reduce error probability on recognizing signals, this study applied finite element method to simulate the propagation of T(0,1) torsional guided wave through the defect on the elbow, proposing time reversal method to analyze in accordance with defects signals, comparing difference of defect echo with and without this method so as to evaluate the feasibility of focusing ability of time reversal method on the elbow and also observing the influence of multiple defects exist in pipes on the focusing results. Time reversal method, a self-focusing technique, it can effectively focus on the spatial and temporal domain. The study results showed that it is beneficial to apply time reversal method to the improvement of signal-to-noise ratio on defect inspection for guided wave system. For instance, if defect exists at the end of elbow, and by comparing with defect reflective amplitude without and with time reversal method, it is clearly to show that the defect reflective amplitude with time reversal method is enhanced compared with that of without time reversal method. In addition to improving the signal-to-noise ratio and making defect easier to identify, it also showed that the wave energy will not be affected by the elbow, and can focus to the defect instead. Besides, when multiple defects exist in pipes, it will not make focusing behavior off the work either. For example, when there are three defects on the elbow pipeline, by using finite element method, the results showed that the focusing ability of wave energy will not be influenced even if it transmit through multiple defects on the pipe of straight part in advance, and can focus to the defect on the elbow part. The thesis also bring up the focusing oriented illustration which can easily to display the wave energy with time reversal method focus on elbow defects direction.
8
Li, Bing-Hung, and 李秉鴻. "A practical appraisal for pipeline inspection using guided waves of torsional mode." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/94958661242189342284.
Повний текст джерелаАнотація:
碩士國立中山大學
機械與機電工程學系研究所
92
Abstract This thesis studies the practical appraisal for pipeline inspection using the guided wave T(0,1) mode. The characteristic of reflected signals from the features of pipeline for various coated materials and fluid-filled pipes are also evaluated. The attenuation and the traveling distance of the guided wave are then calculated from the above-mentioned data for pipeline inspection in petro-chemical industries. In the experimental setup, the torsional mode is excited at one axial location using an array of transducers distributed around the circumference of the 6-inch test pipe. The reflected signals from various features, such as flanges, welds, supports, bends, defects and patches are analyzed at first at specific frequencies in the experiments. The effect of various coated material such as bitumen, PE and insulated material are also evaluated for the propagating torsional mode T(0,1) in the pipe. The results show that the attenuation of reflected signal is heavy for the bitumen-coated case because its viscosity is much higher than the other cases. Furthermore, the effect of pipe contents for defect detection using T(0,1) mode is investigated in this thesis. Various pipe contents, such as water, diesel oil, lubricant and fuel oil are deposit into the test pipe, respectively, to evaluate the influence to T(0,1). For the attenuation evaluation of reflected signal from flange in pipe, the reflected signal from an air-content pipe is measured for reference to compare with the measurements of other pipe contents in the experiments. The results show that the low viscosity liquid deposit in the pipe, such as water, diesel oil and lubricant, has no effect on the torsional mode; while the high viscous of the fuel oil deposit in the pipe attenuates the reflected signal heavily. It became evident that the torsional mode T(0,1) is most suitable for use in fluid-filled pipeline inspection.
Частини книг з теми "Torsional guided wave"
1
Nasedkina, A. A., A. Alexiev, and J. Malachowski. "Numerical Simulation of Ultrasonic Torsional Guided Wave Propagation for Pipes with Defects." In Springer Proceedings in Physics, 475–88. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26324-3_33.
Повний текст джерела
2
Park, Ik Keun, Yong Kwon Kim, Won Joon Song, and Yong Sang Cho. "Application of Torsional Mode of Guided Waves to Long Range Pipe Inspection." In Experimental Mechanics in Nano and Biotechnology, 473–76. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-415-4.473.
Повний текст джерела
3
Yeung, Carman, and Ching Tai Ng. "Analysis of Scattering and Mode Conversion of Torsional Guided Waves by Cracks in Pipes Using Time-Domain Spectral Element Method." In Lecture Notes in Civil Engineering, 1123–30. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-8079-6_105.
Повний текст джерелаТези доповідей конференцій з теми "Torsional guided wave"
1
Sun, Z. "Flexural Torsional Guided Wave Pipe Inspection." In QUANTITATIVE NONDESTRUCTIVE EVALUATION. AIP, 2006. http://dx.doi.org/10.1063/1.2184527.
Повний текст джерела
2
Sun, Zongqi, and Joseph L. Rose. "Ultrasonic Flexural Torsional Guided Wave Focusing in Pipe." In ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-2814.
Повний текст джерелаАнотація:
Ultrasonic flexural torsional guided wave properties, including the excitation and propagation have been studied recently. Natural focusing is one of the major characteristics exhibited by partial loading excitation. With the aid of phased array transducer we propose a wave focusing method to enhance the signal to noise ratio and defect resolution in pipe inspection. With time delays and amplitudes applied to different elements constructive wave interference at specific point can be achieved in order to focus wave energy. Focusing effect is examined by angular profile, which is the circumferential displacement distribution.
3
Sun, Zongqi, Li Zhang, Brian Gavigan, Takahiro Hayashi, and Joseph L. Rose. "Ultrasonic Flexural Torsional Guided Wave Pipe Inspection Potential." In ASME 2003 Pressure Vessels and Piping Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/pvp2003-1849.
Повний текст джерелаАнотація:
The excitation and propagation characteristics of guided wave torsional flexural mode are exploited in this paper. Theoretical computations and experiments are carried out to show the angular profiles of the torsional flexural modes propagation characteristics and the subsequent natural focusing effects. Because of such inherent advantages as less mode conversion and high sensitivity to axial defects, torsional modes and focusing possibilities have great potential in pipe inspection. By combining longitudinal and torsional modes, defect characterizations including defect size, shape etc. can be determined by truly three-dimensional guided wave pipe inspection.
4
Zuo, Yantian, Xiaoying Tang, Houde Yu, Yaozhou Qian, and Jifeng Wang. "Application of Torsional Mode of Ultrasonic Guided Wave in Pressure Pipeline." In ASME 2012 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/pvp2012-78257.
Повний текст джерелаАнотація:
Ultrasonic guided wave technology is presented as a new non-destructive pipeline inspection method for its rapid, long distance inspection and applied to special pipelines which are inaccessible by other conventional NDT methods. It can be widely used in the field of long range pipeline inspection. Dispersion and attenuation characteristics of torsional modes of ultrasonic guided wave in pipeline are presented. Propagation characteristics of T (0, 1) mode at different frequencies are studied. T (0, 1) mode excited by utilizing the magnetostrictive ultrasonic guided wave detection system is applied to detect the defects of pipeline. It can be concluded that the surface condition of the pipeline, the T (0, 1) mode excitation of different patterns and frequency have great effects on defect detection and the distance of guided wave propagation. Multiple factors should be considered to select the optimal frequency and excitation patterns as pipeline inspection in field.
5
Deng, Wenwu, Shengrong Long, Zhinong Li, Jingyi Ren, Yongyue Huang, Lin Gu, and Xuanyu Chen. "Influencing factors on excitation signal of torsional mode magnetostrictive guided wave." In 2020 IEEE 4th Information Technology, Networking, Electronic and Automation Control Conference (ITNEC). IEEE, 2020. http://dx.doi.org/10.1109/itnec48623.2020.9084844.
Повний текст джерела
6
CHEONG, YONG-MOO, and SHIN KIM. "ACOUSTIC PERFORMANCE OF A MAGNETOSTRICTIVE STRIP SENSOR FOR A TORSIONAL GUIDED WAVE." In Proceedings of the International Conference on ANDE 2007. World Scientific Publishing Company, 2008. http://dx.doi.org/10.1142/9789812790194_0070.
Повний текст джерела
7
Wang, Shen, Songling Huang, Zhao Wei, and Guiyun Tian. "Alternating winding magnetostrictive electromagnetic acoustic transducer for pipe torsional guided wave generation." In 2010 IEEE Sensors Applications Symposium (SAS). IEEE, 2010. http://dx.doi.org/10.1109/sas.2010.5439401.
Повний текст джерела
8
Guo, Peng, Hongyuan Li, Zhenhua Tian, and Hong Xu. "Guided Wave Damage Detection in Power-Plant-Tubes by Using Magnetostrictive Transducer Arrays." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45845.
Повний текст джерелаАнотація:
This paper presents an efficient damage detection technique for power-plant-tubes by using guided waves and magnetostrictive transducer arrays. Particularly, our detection technique focuses on the small diameter and thick wall power-plant-tubes, such as superheater tubes, reheater tubes and water wall tubes. Firstly, the damage effects on guided waves in small diameter and thick wall tubes were studied by using three-dimensional finite element method. The wave reflections and mode conversions induced by damage were investigated. Secondly, based on T (0, 1)-F (n, 2) modes, magnetostrictive transducers were designed for guided wave generation and sensing in small diameter and thick wall tubes. The designed magnetostrictive transducers can effectively generate and measure guided waves, especially the non-dispersive torsional T (0, 1) wave mode. Finally, a magnetostrictive transducer array was developed for damage detection in small diameter and thick wall tubes. Through a virtual focusing array imaging algorithm, intensity images were constructed, which can show both the location and size of damage.
9
Longxiang, Zhu, Wang Yuemin, and Sun Fengrui. "Single torsional guided wave excitation in pipes by frequency selection using magnetostrictive sensor technology." In 2013 IEEE 11th International Conference on Electronic Measurement & Instruments (ICEMI). IEEE, 2013. http://dx.doi.org/10.1109/icemi.2013.6743158.
Повний текст джерела
10
Hill, Samuel, Steve Dixon, Sri Harsha Reddy K., Prabhu Rajagopal, and Krishnan Balasubramaniam. "A new electromagnetic acoustic transducer design for generating torsional guided wave modes for pipe inspections." In 43RD ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLUME 36. Author(s), 2017. http://dx.doi.org/10.1063/1.4974597.
Повний текст джерела