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Статті в журналах з теми "Crack location detection"
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Kim, Byeong-Cheol, and Byung-Jik Son. "Crack Detection of Concrete Images Using Dilatation and Crack Detection Algorithms." Applied Sciences 13, no. 16 (August 14, 2023): 9238. http://dx.doi.org/10.3390/app13169238.
Повний текст джерелаАнотація:
Crack detection in structures is an important and time-consuming element of monitoring the health of structures and ensuring structural safety. The traditional visual inspection of structures can be unsafe and may produce inconsistent results. Thus, there is a need for a method to easily and accurately identify and analyze cracks. In this study, algorithms for automatically detecting the size and location of cracks in concrete images were developed. Cracks were automatically detected in a total of 10 steps. In steps 5 and 9, two user algorithms were added to increase crack detection accuracy, where 1000 crack images and 1000 non-crack images were used, respectively. In the crack image, 100% of the cracks were detected, but 95.3% of the results were very good, even if the results that were not bad in terms of quality were excluded. In addition, the accuracy of detecting non-crack images was also very good (96.9%). Thus, it is expected that the crack detection algorithm presented in this study will be able to detect the location and size of cracks in concrete. Moreover, these algorithms will help in observing the soundness of structures and ensuring their safety.
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Nwosu, D. I., A. S. J. Swamidas, and J. Y. Guigne´. "Dynamic Response of Tubular T-Joints Under the Influence of Propagating Cracks." Journal of Offshore Mechanics and Arctic Engineering 118, no. 1 (February 1, 1996): 71–78. http://dx.doi.org/10.1115/1.2828804.
Повний текст джерелаАнотація:
This paper presents an analytical study on the vibration response of tubular T-joints for detecting the existence of cracks along their intersections. The ABAQUS finite element program was utilized for carrying out the analysis. Frequency response functions were obtained for a joint with and without cracks. The joint was modeled with 8-node degenerate shell elements having 5 degrees of freedom per node. Line spring elements were used to model the crack. The exact crack configuration (semielliptical shape, Fig. 5(b)), as observed from numerous experimental fatigue crack investigations at the critical location, has been achieved through a mapping function, that allows a crack in a planar element to be mapped on to the tube surface. The natural frequency changes with respect to crack depth show little changes, being 4.82 percent for a 83-percent crack depth for the first mode. On the other hand, significant changes have been observed for bending moment and curvature as a function of crack depth. For an 83-percent chord thickness crack, a 97-percent change in bending moment at points around the crack vicinity, and 34.15 to 78 percent change in bending moments, for those locations far away from the crack location, have been observed. Natural frequency change should be combined with other modal parameters such as “bending moment (or bending strain)” and “curvature” changes for crack detection. The presence of the crack can be detected at locations far away from the crack location using such sensors as strain gages.
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Wang, Fei, Xue Zeng Zhao, and Jia Ying Chen. "Detection of Multiple Cracks in Triangular Cantilevers Based on Frequency Measurements." Key Engineering Materials 324-325 (November 2006): 259–62. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.259.
Повний текст джерелаАнотація:
Triangular cantilevers are used as small force sensors. Prediction of location and size of multiple cracks from experimental results will be of value to users and designers of cantilever deflection force sensors. We extend a method for prediction of location and size of multiple cracks in rectangular cantilevers to deal with triangular cantilevers in this paper. The cracks are assumed to introduce local flexibility change and are modeled as rotational springs. The beam is divided into a number of segments, and each segment is associated with a damage index, which can be calculated through the relationship between the damage index and strain energy of each segment and the changes in the frequencies caused by the cracks. The location of cracks can be obtained with high accuracy with sufficient segment numbers. The size of a crack can be calculated through the relationship between the crack size and its stiffness, which can be obtained from the damage index related to the crack. The maximum error in prediction of the crack position in the case of double cracks is less than 15%, and it is less than 25% in prediction of the crack size.
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Khalkar, V., and S. Ramachandran. "The effect of crack geometry on non-destructive fault detection of EN 8 and EN 47 cracked cantilever beam." Noise & Vibration Worldwide 50, no. 3 (March 2019): 92–100. http://dx.doi.org/10.1177/0957456519834537.
Повний текст джерелаАнотація:
Since long it has been observed that the size of the crack in structures increases with time, and finally, it may lead to its catastrophic failure. Hence, it is crucial to do the vibration study of cracked structures with regard to vibration-based crack detection and the classification of cracks. So far, vibration-based non-destructive testing method is applied to many spring steel cracked cantilever beams for its possible crack detection. However, the effect of various kinds of practical cracks, that is, V-shaped and U-shaped, on the applicability of these methods has been overlooked. To investigate this issue, artificially cracks are made on the cantilever beam. By free vibration analysis, the effect of crack geometry, crack depth, and crack location on natural frequency is investigated. The natural frequency results obtained from V-shaped and U-shaped models for the same crack configurations are compared with each other and it is revealed that the results are not much sensitive for the change of crack geometry. Hence, it is clear that free vibration-based crack detection method approximately predicts the crack parameters, that is, crack location and crack depth, in structures irrespective of the crack geometry. It is also found that for the same configuration, results of natural frequency are comparatively on the lower side for U-shaped crack models than V-shaped crack models. In this study, the natural frequency of each cracked case is computed by a theoretical method and numerical method and shows good agreement. Finally, it is also observed that structural integrity of a cracked cantilever beam is a function of crack location.
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Zhao, Yiming, Jing Yan, Yanxin Wang, Qianzhen Jing, and Tingliang Liu. "Porcelain Insulator Crack Location and Surface States Pattern Recognition Based on Hyperspectral Technology." Entropy 23, no. 4 (April 20, 2021): 486. http://dx.doi.org/10.3390/e23040486.
Повний текст джерелаАнотація:
A porcelain insulator is an important part to ensure that the insulation requirements of power equipment can be met. Under the influence of their structure, porcelain insulators are prone to mechanical damage and cracks, which will reduce their insulation performance. After a long-term operation, crack expansion will eventually lead to breakdown and safety hazards. Therefore, it is of great significance to detect insulator cracks to ensure the safe and reliable operation of a power grid. However, most traditional methods of insulator crack detection involve offline detection or contact measurement, which is not conducive to the online monitoring of equipment. Hyperspectral imaging technology is a noncontact detection technology containing three-dimensional (3D) spatial spectral information, whereby the data provide more information and the measuring method has a higher safety than electric detection methods. Therefore, a model of positioning and state classification of porcelain insulators based on hyperspectral technology is proposed. In this model, image data were used to extract edges to locate cracks, and spectral information was used to classify the surface states of porcelain insulators with EfficientNet. Lastly, crack extraction was realized, and the recognition accuracy of cracks and normal states was 96.9%. Through an analysis of the results, it is proven that the crack detection method of a porcelain insulator based on hyperspectral technology is an effective non-contact online monitoring approach, which has broad application prospects in the era of the Internet of Things with the rapid development of electric power.
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Yuan, Yingtao, Zhendong Ge, Xin Su, Xiang Guo, Tao Suo, Yan Liu, and Qifeng Yu. "Crack Length Measurement Using Convolutional Neural Networks and Image Processing." Sensors 21, no. 17 (September 1, 2021): 5894. http://dx.doi.org/10.3390/s21175894.
Повний текст джерелаАнотація:
Fatigue failure is a significant problem in the structural safety of engineering structures. Human inspection is the most widely used approach for fatigue failure detection, which is time consuming and subjective. Traditional vision-based methods are insufficient in distinguishing cracks from noises and detecting crack tips. In this paper, a new framework based on convolutional neural networks (CNN) and digital image processing is proposed to monitor crack propagation length. Convolutional neural networks were first applied to robustly detect the location of cracks with the interference of scratch and edges. Then, a crack tip-detection algorithm was established to accurately locate the crack tip and was used to calculate the length of the crack. The effectiveness and precision of the proposed approach were validated through conducting fatigue experiments. The results demonstrated that the proposed approach could robustly identify a fatigue crack surrounded by crack-like noises and locate the crack tip accurately. Furthermore, crack length could be measured with submillimeter accuracy.
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Sethi, Rabinarayan, S. K. Senapati, and Dayal R. Parhi. "Structural Damage Detection by Fuzzy Logic Technique." Applied Mechanics and Materials 592-594 (July 2014): 1175–79. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1175.
Повний текст джерелаАнотація:
In this paper, a novel approach for detecting crack location and its intensity in cantilever beam by Fuzzy logic techniques is established. The analysis has been done by using ANSYS FE software. The fuzzy controller with Bell shaped membership functions are used here which consists of three input parameters are relative deviation of first three natural frequencies and two output parameters are relative crack depth and relative crack location respectively. A series of fuzzy rules are resulting from vibration parameters which are finally used for prediction of crack location and its intensity. This method provides the knowledge towards the detection, location and characterization of the damage in the cantilever beam.
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Xu, Guoyan, Xu Han, Yuwei Zhang, and Chunyan Wu. "Dam Crack Image Detection Model on Feature Enhancement and Attention Mechanism." Water 15, no. 1 (December 25, 2022): 64. http://dx.doi.org/10.3390/w15010064.
Повний текст джерелаАнотація:
Dam crack detection can effectively avoid safety accidents of dams. To solve the problem that the dam crack image samples are not available and the traditional algorithm detects cracks with low accuracy, we provide a dam crack image detection model based on crack feature enhancement and attention mechanism. Firstly, we expand the dam crack image dataset through a generative adversarial network based on crack feature enhancement (Cracks Enhancements GAN, CE-GAN). It can fully expand the dam crack data samples and improve the quality of the training data. Secondly, we propose a crack image detection model based on the attention mechanism (Attention-based Faster-RCNN, AF-RCNN). The attention mechanism is added in the crack detection module to give different weights to the proposal boxes around the crack target and fuse the candidate boxes with high weights to accurately detect the crack target location. The experimental results show that our algorithm achieves 81.07% mAP on the expanded dam crack dataset, which is 8.39% higher than the original Faster-RCNN algorithm. The detection accuracy is significantly improved compared with other traditional dam crack detection algorithm models.
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Ahn, Ju-Hun, Yong-Chan Lee, Se-Min Jeong, Han-Na Kim, and Chang-Yull Lee. "Crack Detecting Method Based on Grid-Type Sensing Networks Using Electrical Signals." Sensors 23, no. 13 (July 2, 2023): 6093. http://dx.doi.org/10.3390/s23136093.
Повний текст джерелаАнотація:
Cracks have a primary effect on the failure of a structure. Therefore, the development of crack sensors with high accuracy and resolution and cracks detection method are important. In this study, the crack sensors were fabricated, and the crack locations were detected with the electrical signal of the crack sensor. First, a metal grid-type micro-crack sensor based on silver was fabricated. The sensor is made with electrohydrodynamics (EHD) inkjet printing technology, which is well known as the next generation of printed electronics technology. Optimal printing conditions were established through experiments, and a grid sensor was obtained. After that, single cracks and multiple cracks were simulated on the sensor, and electrical signals generated from the sensor were measured. The measured electrical signal tracked the location of the cracks in three steps: simple cross-calculation, interpolation, and modified P-SPICE. It was confirmed that cracks could be effectively found and displayed using the method presented in this paper.
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Fang, Zhi Hua, and Xiang Yang Liu. "Research on Recognition Methods of Crack Damage from Beam Based on the Vibration Modal." Applied Mechanics and Materials 578-579 (July 2014): 1024–27. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.1024.
Повний текст джерелаАнотація:
Structural crack damage will degrade its carrying capacity, and affect the security of the structure. Thus early detection of crack damage is a guarantee of the structure safety. Cracks can change the vibration characteristics of the structure, therefore we proposed a method of identifying the crack damage based on the vibration modal. Take both ends fixed beam as an example, through establish the finite element models of crack-free beam and the crack beam with different location and different depth, we calculate the displacement modal parameters of beam before and after the damage, analyze the variation law of displacement modal horizontal component of change and displacement modal Axial displacement difference rate of change varies with crack depth and location, results show that the variation of displacement modal horizontal component and the change rate of displacement modal Axial displacement difference along crack direction are sensitive to cracks location and depth, these can be used as a basis for identification of beam’s crack damage.
Дисертації з теми "Crack location detection"
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LaBerge, Kelsen. "Exploratory Research on a Method for Detecting Shaft Radial Cracks: Severity, Location, and Feasibility." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1228403434.
Повний текст джерела
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Zacarias, Alisson Teixeira. "Determinação da variação de rigidez em placas, através da metodologia dos observadores de estados /." Ilha Solteira : [s.n.], 2008. http://hdl.handle.net/11449/94563.
Повний текст джерелаАнотація:
Orientador: Gilberto Pechoto de MeloBanca: Vicente Lopes Júnior
Banca: Raquel Santini Leandro Rade
Resumo: Hoje em dia um dos fatores de interesse das indústrias no desenvolvimento de novas técnicas de detecção e localização de falhas é a preocupação com a segurança de seus sistemas, tendo-se a necessidade de supervisão e monitoramento de modo que as falhas sejam detectadas e corrigidas o mais rápido possível. Verifica-se na prática que determinados parâmetros dos sistemas podem variar durante o processo, devido a características específicas ou o desgaste natural de seus componentes. Sabe-se também que, mesmo nos sistemas bem projetados, a ocorrência de trincas em alguns componentes pode provocar perdas econômicas ou conduzir a situações perigosas. Os observadores de estado podem reconstruir os estados não medidos do sistema, desde que os mesmos sejam observáveis, tornando possível, desta forma, estimar as medidas nos pontos de difícil acesso. A técnica dos observadores de estado consiste em desenvolver um modelo para o sistema em análise e comparar a estimativa da saída com a saída medida, a diferença entre os dois sinais presentes resulta em um resíduo que é utilizado para análise. Neste trabalho foi montado um banco de observadores associado a um modelo de trinca de modo a acompanhar o progresso da mesma. Os resultados obtidos através de simulações computacionais em uma placa engastada discretizada pela técnica dos elementos finitos e as análises experimentais realizadas foram bastante satisfatórios, validando a metodologia desenvolvida.
Abstract: Nowadays a main factor of interest in industries in the development of new techniques for detection and localization of faults is the concern with the security of its systems. There is the need of supervising and monitoring the machines to detect and correct the fault as soon as possible. In practice it is verified that some determined parameters of the systems can vary during the process, due to the specific characteristics or the natural wearing of its components. It is known that even in well-designed systems the occurrence of cracks in some components can induce economic losses or lead to dangerous situations. The state observers methodology can reconstruct the unmeasured states of the system, since they are observable, becoming possible in this way to estimate the measures at points of difficult access. The technique of state observers consists of developing a model for the system under analysis and to compare the estimated with the measured exit, and the difference between these two signals results in a residue that is used for analysis. In this work was set up a bank of observers associated to a model of crack in order to follow its progress. The results obtained through computational simulations in a cantilever plate discretized by using the finite elements technique and the accomplished experimental analysis were sufficiently satisfactory, validating the developed methodology.
Mestre
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Zacarias, Alisson Teixeira [UNESP]. "Determinação da variação de rigidez em placas, através da metodologia dos observadores de estados." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/94563.
Повний текст джерелаАнотація:
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zacarias_at_me_ilha.pdf: 587117 bytes, checksum: 4a907603292d52ff41cf7df3b7718be5 (MD5)Hoje em dia um dos fatores de interesse das indústrias no desenvolvimento de novas técnicas de detecção e localização de falhas é a preocupação com a segurança de seus sistemas, tendo-se a necessidade de supervisão e monitoramento de modo que as falhas sejam detectadas e corrigidas o mais rápido possível. Verifica-se na prática que determinados parâmetros dos sistemas podem variar durante o processo, devido a características específicas ou o desgaste natural de seus componentes. Sabe-se também que, mesmo nos sistemas bem projetados, a ocorrência de trincas em alguns componentes pode provocar perdas econômicas ou conduzir a situações perigosas. Os observadores de estado podem reconstruir os estados não medidos do sistema, desde que os mesmos sejam observáveis, tornando possível, desta forma, estimar as medidas nos pontos de difícil acesso. A técnica dos observadores de estado consiste em desenvolver um modelo para o sistema em análise e comparar a estimativa da saída com a saída medida, a diferença entre os dois sinais presentes resulta em um resíduo que é utilizado para análise. Neste trabalho foi montado um banco de observadores associado a um modelo de trinca de modo a acompanhar o progresso da mesma. Os resultados obtidos através de simulações computacionais em uma placa engastada discretizada pela técnica dos elementos finitos e as análises experimentais realizadas foram bastante satisfatórios, validando a metodologia desenvolvida.
Nowadays a main factor of interest in industries in the development of new techniques for detection and localization of faults is the concern with the security of its systems. There is the need of supervising and monitoring the machines to detect and correct the fault as soon as possible. In practice it is verified that some determined parameters of the systems can vary during the process, due to the specific characteristics or the natural wearing of its components. It is known that even in well-designed systems the occurrence of cracks in some components can induce economic losses or lead to dangerous situations. The state observers methodology can reconstruct the unmeasured states of the system, since they are observable, becoming possible in this way to estimate the measures at points of difficult access. The technique of state observers consists of developing a model for the system under analysis and to compare the estimated with the measured exit, and the difference between these two signals results in a residue that is used for analysis. In this work was set up a bank of observers associated to a model of crack in order to follow its progress. The results obtained through computational simulations in a cantilever plate discretized by using the finite elements technique and the accomplished experimental analysis were sufficiently satisfactory, validating the developed methodology.
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LaBerge, Kelsen. "Exploratory research on a method for detecting shaft radial cracks severity, location, and feasibility /." online version, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=case1228403434.
Повний текст джерела
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Kulkarni, Raghavendra B. "Inverse problems solution using spectral finite element methods." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5471.
Повний текст джерелаАнотація:
Inverse problems are very challenging as these problems involve, finding the cause by analyzing the effects. In structural dynamics problems, the effects are normally measured in terms of dynamic responses in structures. These responses which are used to find the cause generally have partial data, embedded with measurement noise, and are truncated. Due to these problems, inverse problems are generally ill-posed in most cases as against forward problems.
In this dissertation, we solve five different types of inverse problems involving high-frequency transient loads. All these problems are solved using the time-domain spectral element method (TSFEM) along with experimental or numerically simulated responses.
The dissertation starts with the formulation of the forward problem, which is obtaining the responses from known input forces. The general formulation of TSFEM of composite Timoshenko beam is derived. The isotropic beam formulation is shown as a special case in this formulation.
Five different inverse problems solved in the thesis are:
1. Force identification problem: A new algorithm is developed using a 1-D waveguide, involving an eight noded spectral finite element. The force identification is carried out, using a few measured responses on the structure, and using TSFEM we reconstruct the input force. This is followed by a portal frame example to demonstrate the wave reflection complexities. New procedures are developed to use various types of response data like displacement, velocity, acceleration, and strain to identify the force.
2. Material identification problem: A new procedure making use of the developed TSFEM, few responses, and nonlinear least square techniques are used to determine the material properties. Also, we show the case, in which we derive the material properties without force input consideration.
3. Crack location detection problem: A new procedure is developed using TSFEM and mechanics of crack. Three methods are described, in which the first method uses only responses and wave speeds to determine the location of the crack. In the second method, force reconstruction using the measured responses is carried out and this, in turn, is used to determine the location of the crack. The third method uses the residues of the actual force and the reconstructed forces using the healthy beam matrices and cracked beam responses. A new procedure to identify the crack location using a general force input pulse having many frequency components is also developed.
4. Material defect identification: Material defects like voids or density changes are identified using TSFEM. Location and magnitude of defect are identified using response computation and using the method of residues.
5. Porous location and identification in a composite material: TSFEM is used to construct a porous element and this is used along with a healthy beam to generate the responses. A force reconstruction algorithm is used to identify the location of the porous element. The Force residue method to identify the location of the defect is also demonstrated. Further, we make use of the material identification algorithm with a few modifications to evaluate all the parameters for the porous element.
Частини книг з теми "Crack location detection"
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Sun, Zhaoyun, Lili Pei, Bo Yuan, Yaohui Du, Wei Li, and Yuxi Han. "Pavement Crack Detection and Quantification Based on Scanning Grid and Projection Method." In Lecture Notes in Civil Engineering, 273–81. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1260-3_24.
Повний текст джерелаАнотація:
AbstractPavement cracks are difficult to monitor and quantify due to their complex texture and easy to be disturbed by noise and illumination. To solve this problem, a road crack monitoring and quantification method based on vehicle video is proposed. First, a method for extracting morphological features of dynamic road cracks is proposed. Combine automated vehicle-mounted equipment with GPS signals to obtain crack images with location information. Then, a calculation algorithm of crack parameters based on the combination of UK scanning grid and projection method is proposed, which uses the reverse engineering principle of perspective transformation to correct the image and divides the entire image into grid blocks. Finally, based on the analysis of different crack grades, the crack distress evaluation method is improved. The experimental results show that the proposed method has strong reliability and adaptability and achieves high-frequency and wide-range road detection.
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Ding, Mengling, and Kwanghee Won. "Crack Detection and Location Estimation Using a Convolutional Neural Network." In Communications in Computer and Information Science, 184–88. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-81638-4_15.
Повний текст джерела
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Zhang, Zhifen, Rui Qin, Yujiao Yuan, Wenjing Ren, Zhe Yang, and Guangrui Wen. "Acoustic Emission-Based Weld Crack In-situ Detection and Location Using WT-TDOA." In Transactions on Intelligent Welding Manufacturing, 49–73. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6502-5_3.
Повний текст джерела
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Díaz, Jorge G., and Deisy C. Paez. "Identification of Crack Tip Location Using Edge Detection Algorithms and Artificially Generated Displacement Fields." In Lecture Notes in Electrical Engineering, 1–8. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-53021-1_1.
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Aggelis, Dimitrios G., Markus G. R. Sause, Pawel Packo, Rhys Pullin, Steve Grigg, Tomaž Kek, and Yu-Kun Lai. "Acoustic Emission." In Structural Health Monitoring Damage Detection Systems for Aerospace, 175–217. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72192-3_7.
Повний текст джерелаАнотація:
AbstractAcoustic emission (AE) is one of the most promising methods for structural health monitoring (SHM) of materials and structures. Because of its passive and non-invasive nature, it can be used during the operation of a structure and supply information that cannot be collected in real time through other techniques. It is based on the recording and study of the elastic waves that are excited by irreversible processes, such as crack nucleation and propagation. These signals are sensed by transducers and are transformed into electric waveforms that offer information on the location and the type of the source. This chapter intends to present the basic principles, the equipment, and the recent trends and applications in aeronautics, highlighting the role of AE in modern non-destructive testing and SHM. The literature in the field is vast; therefore, although the included references provide an idea of the basics and the contemporary interest and level of research and practice, they are just a fraction of the total possible list of worthy studies published in the recent years.
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Ranjan, Rajeev. "Dynamic Behaviour and Crack Detection of a Multi Cracked Rotating Shaft using Adaptive Neuro-Fuzzy-Inference System." In Fuzzy Systems, 1540–51. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1908-9.ch062.
Повний текст джерелаАнотація:
The presence of crack changes the physical characteristics of a structure which in turn alter its dynamic response characteristics. So it is important to understand dynamics of cracked structures. Crack depth and location are the main parameters influencing the vibration characteristics of the rotating shaft. In the present study, a technique based on the measurement of change of natural frequencies has been employed to detect the multiple cracks in rotating shaft. The model of shaft was generated using Finite Element Method. In Finite Element Analysis, the natural frequency of the shaft was calculated by modal analysis using the software ANSYS. The Numerical data were obtained from FEA, then used to train through Adaptive Neuro-Fuzzy-Inference System. Then simulations were carried out to test the performance and accuracy of the trained networks. The simulation results show that the proposed ANFIS estimate the locations and depth of cracks precisely.
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Li, Xinhai, Qifeng Luo, Qingzhu Zeng, Xinxiong Zeng, Chao Yan, and Kai Zhang. "Composite Insulator Defect Identification Method Using Improved RCNN Convolution Kernel." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220002.
Повний текст джерелаАнотація:
The detection of composite insulator defects in substations still relies on manual inspection. In this paper, we propose a detection method for insulator crack shape features by improving the RCNN convolution kernel. The method can meet the premise of insufficient training sample data, but also can get better CNN training effect, and finally achieve accurate crack recognition. In the training phase, the RGB three-channel decomposition method is used to expand the training data set; the median filtering method is used to remove the noise; the improved convolutional kernel is used to train the CNN; in the test phase, the images are decomposed by RGB three-channel decomposition and input to CNN to get the exact crack center coordinates and length; the NMS algorithm is used to de-weight the images to get the final crack recognition results. The example analysis shows that the method in this paper can still achieve good recognition accuracy and accurately identify the specific location of cracks under the premise of insufficient training samples.
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Ammari, Habib, Elie Bretin, Josselin Garnier, Hyeonbae Kang, Hyundae Lee, and Abdul Wahab. "Backpropagation and Multiple Signal Classification Imaging of Small Inclusions." In Mathematical Methods in Elasticity Imaging. Princeton University Press, 2015. http://dx.doi.org/10.23943/princeton/9780691165318.003.0006.
Повний текст джерелаАнотація:
This chapter deals with direct imaging of small inclusions and cracks in the static regime, focusing on MUSIC- and migration-type algorithms for detecting the small defects. MUSIC, reverse-time migration, and Kirchhoff migration algorithms take advantage of the smallness of the elastic inclusions. Even though only the two-dimensional case is considered, the same algorithms can be applied in three dimensions. These direct location search algorithms are extended to the general case of linear isotropic elasticity. After describing least-squares algorithms for locating small elastic inclusions, the chapter introduces a MUSIC-type location search algorithm in the static regime and extends it to the time-harmonic regime. It also performs three-dimensional simulations to illustrate relevant features of the MUSIC algorithm.
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Gu, Jing, and Ying-hui Li. "A Bridge Disease Detection Method Based on Improved YOLOX Algorithm." In Advances in Transdisciplinary Engineering. IOS Press, 2023. http://dx.doi.org/10.3233/atde230084.
Повний текст джерелаАнотація:
To address the issue of the SPP structure in the YOLOX network being unable to perfectly express the spatial structure of diseases during bridge disease detection, resulting in poor detection performance for irregular and elongated targets, a YOLOX bridge disease detection algorithm based on CS pooling is proposed. The algorithm uses cross-pooling and strip-pooling on the output feature map of the Backbone, and then fuses them, fully combining the local and elongated features as well as the spatial location features of the feature map, improving the expressive ability of the feature map, making it more suitable for bridge disease detection. The experimental results show that the improved model based on CS pooling YOLOX achieves better detection results, with a 2.61% improvement in detection accuracy compared to the YOLOX network, and the detection accuracy of cracks and weathering is the highest. This verifies the effectiveness of the algorithm.
Тези доповідей конференцій з теми "Crack location detection"
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Zhang, Pugen, Shaoping Zhou, and Wenchao Lv. "Detection of Defects in Pipes and Elbows Using Guided Waves." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28512.
Повний текст джерелаАнотація:
This paper deals with the detection of circumferential cracks of different areas in elbow pipes using the guided waves in mode of L(0,2) which are excited by a piezoelectric transducer. The experimental results show that the circumferential cracks can be located in axial position for bend straight side by the reflected echo of defects in the pipes. The detection sensitivity depends on the location of the cracks in bend areas of the pipes. It is easier to detect cracks in the extradose of elbow while harder to detect those in the other locations of the bend. There is a relationship between the detection sensitivity and the frequency of guided waves. The signal-to-noise ratio when detecting the crack before and beyond elbows is highest for the frequency ranges from 120kHz to 130kHz; the crack on the intradose of elbow can be inspected more effectively when using frequencies near 80kHz. Therefore, the combination of high-frequency and low-frequency is used to inspect elbows. The propagation behaviors in elbows are investigated by using numerical simulation. The results of simulation intuitively explain the experimental phenomenon.
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Bonnin-Pascual, F., and A. Ortiz. "Combination of weak classifiers for metallic corrosion detection and guided crack location." In Factory Automation (ETFA 2010). IEEE, 2010. http://dx.doi.org/10.1109/etfa.2010.5641267.
Повний текст джерела
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Cai, Youfa, Xing Fu, Yanna Shang, and Jingxin Shi. "Methods for Long-Distance Crack Location and Detection of Concrete Bridge Structures." In 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC). IEEE, 2018. http://dx.doi.org/10.1109/icivc.2018.8492764.
Повний текст джерела
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McKee, Kristoffer K., and C. James Li. "Rotor Transverse Crack Detection and Diagnosis Using Embedded Modeling." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43504.
Повний текст джерелаАнотація:
This study proposes an embedded modeling methodology for identifying the crack-induced local stiffness reduction in a shaft from its horizontal and vertical vibrations. An embedded model integrating a dynamic model of the rotor system, and the unknown local stiffness reduction in the form of a universal function approximator i.e., neural network, is established. As a FEM model, it can describe rotors of complex geometry. A solution method is then established to identify the local stiffness reduction of the shaft due to a crack. Subsequently, a method is then used to find the location and size of the crack along the shaft. Simulated studies were conducted to demonstrate that the crack induced stiffness reduction of a Jeffcott rotor system can be identified, and the location, size and shape of the crack can be estimated by the proposed method with high level of accuracy.
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Altammar, Hussain, Anoop Dhingra, and Sudhir Kaul. "Use of Wavelets for Mixed-Mode Damage Diagnostics in Warren Truss Structures." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-34017.
Повний текст джерелаАнотація:
The use of the wavelet transform has been gaining widespread acceptance over the last decade as a valuable tool for damage detection. This paper investigates the use of wavelets for detecting mixed-mode, also known as combined mode, cracks in truss structures. The propagation of an open, mixed-mode crack is simulated by using a macroscopic model of damage that is combined with a finite element model of the Warren truss. The natural modes of the truss with varying levels of damage are then used to determine crack location on a specific member of the truss. A damage detection algorithm is developed and the influence of multiple parameters such as truss geometry, crack geometry, number of truss members, etc. is investigated. A direct correlation between damage severity and the magnitude of wavelet coefficients is found for a predefined damage location. It is observed that the proposed damage detection algorithm can be used to successfully detect mixed-mode cracks even in the presence of noise, and even when a relatively coarse sampling of natural modes is used. Multiple simulations are presented and some shortcomings of the proposed algorithm are also discussed in detail.
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Meng, G., and Eric J. Hahn. "Dynamic Response of a Cracked Rotor With Some Comments on Crack Detection." In ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1994. http://dx.doi.org/10.1115/94-gt-029.
Повний текст джерелаАнотація:
By considering time dependent terms as external excitation forces, the approximate dynamic response of a cracked horizontal rotor is analysed theoretically and numerically. The solution is good for small cracks and small vibrations in the stable operating range. For each steady state harmonic component the forward and backward whirl amplitudes, the shape and orientation of the elliptic orbit and the amplitude and phase of the response signals arc analysed, taking into account the effect of crack size, crack location, rotor speed and unbalance. It is found that the crack causes backward whirl, the amplitude of which increases with the crack. For a cracked rotor, the response orbit for each harmonic component is an ellipse, the shape and orientation of which depends on the crack size. The influence of the crack on the synchronous response of the system can be regarded as an additional unbalance whereupon, depending on the speed and the crack location, the response amplitude differs from that of the uncracked rotor. The nonsynchronous response provides evidence of crack in the sub-critical range, but is too small to be detected in the supercritical range. Possibilities for crack detection over the full speed range include the additional average (the constant) response component, the backward whirl of the response, the ellipticity of the orbit, the angle between the major axis and the vertical axis and the phase angle difference between vertical and horizontal vibration signals.
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Rehman, A. U., J. A. Rongong, and K. Worden. "Detection of Damage in Repeating Structures." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23351.
Повний текст джерелаАнотація:
Repeating structures in the form of multiple-bladed rotors are used widely in turbomachinery. Damage to blades can have significant consequences but can be difficult to identify in normal operation. This paper introduces an approach for identifying small defects such as cracks in a repeating structure that may be applicable to the limited data obtainable from developing techniques such as blade tip-timing. In order to understand the key issues involved, this initial work involves a numerical study of a simple comb-like repeating structure rather than a bladed rotor. Changes to the system modeshapes and mode order arising from damage are related to the location and severity of damage. Damage, in the form of small, open cracks, is modelled using different techniques such as material removal, periodic reduction in modulus of elasticity of selected elements at the required location and mass modification. Damage indices based on differences in the Modal Assurance Criterion (MAC) that give a measure of the change in the modeshapes are introduced. MAC matrices are obtained using a reduced number of data points. The damage index is obtained from the Frobenius norm of MAC matrix subtracted from (1) the AutoMAC of reference model without crack and (2) the identity matrix. A clear correlation between the damage indices and crack depth / location is shown. In order to account for mistuning in real repeating structures, the performance when the assembly is subjected to inhomogeneous temperature distributions is also considered.
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Ratan, Santosh, Haim Baruh, and Jorge Rodriguez. "On-Line Identification and Location of Rotor Cracks." In ASME 1993 Design Technical Conferences. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/detc1993-0042.
Повний текст джерелаАнотація:
Abstract A new method is proposed to detect and locate a crack in a rotor system. A vector quantity ‘Residue’ is defined using the measured vibration response of the rotor system and the modeled system matrices. It is shown that the non-zero elements of ‘Residue’ correspond to the nodes encompassing the element carrying the crack. Although, the derivation of ‘Residue’ is based on the linear model of the rotor system, the response due to the non-linearity caused by the breathing of the crack causes only a small amount of contamination. To investigate the robustness of the proposed method, a sensitivity analysis is conducted. It is found that the method could detect a crack of as small depth as 4% of the shaft diameter. The effects of light damping and the order of finite element discretization on the detection result are also investigated, and are found to be small.
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Sekhar, A. S., and P. Balaji Prasad. "Crack Identification in a Cantilever Beam Using Coupled Response Measurements." In ASME 1997 Turbo Asia Conference. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-aa-025.
Повний текст джерелаАнотація:
Identification of crack location and magnitude through measurement in changes in system characteristics, such as modal measurements has been studied by various researchers. In the present work based on the new method proposed by Gounaris et al (1996) for crack detection through coupled response measurements, experiments were carried out on a cracked cantilever beam for eigenfrequencies, bending and axial response measurements. It has been observed that the rate of change of direct response (bending) is much less at small cracks while that of the coupled response (axial) changes, substantially allowing diagnoses of smaller cracks.
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Haji, Z. N., and S. O. Oyadiji. "Detection of Cracks in Stationary Rotors via the Modal Frequency Changes Induced by a Roving Disc." In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20611.
Повний текст джерелаАнотація:
In this study, a crack identification approach based on a finite element cracked model is presented to identify the location and depth ratios of a crack in rotor systems. A Bernoulli-Euler rotor carrying an auxiliary roving disc has been used to model the cracked rotor, in which the effect of a transverse open crack is modelled as a time-varying stiffness matrix. In order to predict the crack location in the rotor-disc-bearing system, the suggested approach utilises the variation of the normalized natural frequency curves versus the non-dimensional location of a roving disc which traverses along the rotor span. The merit of the suggested approach is to identify the location and sizes of a crack in a rotor by determining only the natural frequencies of the stationary rotor system. The first four natural frequencies are employed for the identification and localisation of a crack in the stationary rotor. Furthermore, this approach is not only efficient and practicable for high crack depth ratios but also for small crack depth ratios and for a crack close to or at the node of mode shapes, where natural frequencies are unaffected.
Звіти організацій з теми "Crack location detection"
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Denowh, Chantz, and David Futch. PR-652-213801-R01 Technology Assessment for Detection of Fatigue Cracks on Heavy Wall Gas Risers. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2022. http://dx.doi.org/10.55274/r0012198.
Повний текст джерелаАнотація:
The objective of the SPIM-1-2 project was to identify and evaluate the most promising technologies for detecting and sizing fatigue cracks on heavy wall pipelines and risers, preferably without liquid coupling. To complete this evaluation, six full-scale heavy wall pipe samples were fabricated, and a range of fatigue cracks generated in circumferential welds using resonant fatigue. These samples were used in blind test trials on several available inspection technologies in a pull-through testbed. The technologies were evaluated on their ability to detect and size the fatigue cracks generated from resonant fatigue. At the conclusion of the SPIM-1-2 project, the fatigue cracks in the heavy-wall circumferential welds were available to PRCI members to continue testing and development of inspection technologies. At the conclusion of the SPIM-1-2 project, the actual fatigue crack locations and sizes were not included in the final reports to protect the blind nature of the six pipes samples. A follow-up effort under NDE-2-2 was conducted to gather metallurgical truth for several of the fatigue cracks and generate a comprehensive report that evaluated the inspection technology results from SPIM-1-2 against this truth data.
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Ginzel. L51748 Detection of Stress Corrosion Induced Toe Cracks-Advancement of the Developed Technique. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 1996. http://dx.doi.org/10.55274/r0010659.
Повний текст джерелаАнотація:
In the past few years an ongoing problem has existed with stress corrosion cracking (SCC) in pipelines around the world. Several member companies of the Pipeline Research Council International, Inc. have experienced multiple incidents as a result of ERW defects and SCC. TCPL is running a series of hydrostatic tests and trial digs to identify the most severely affected areas. These excavations and failure studies have ascertained that most of the SCC causing failure has been on the outside diameter of long seam welded pipe at the edge of the weld. Defects at that location are known as "Toe-Cracks" Ginzel has developed an ultrasonic inspection technique that will detect both SCC colonies and toe cracks in long seam pipe. The main design objective for this research project was the selection and placement of ultrasonic transducers to combine weld, plate thickness and lamination inspection, along with SCC detection and sizing. Examination of sample pipe sections to demonstrate its success is reported. The primary stages for this research project are: �Assemble test equipment Establish test procedure System trials and data collection Evaluation of system performance and collected data Correlation of test data - Results
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Hayford. L51566 Ultralow Frequency Eddy Current Instrument for the Detection and Sizing of Stress Corrosion Cracks. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 1988. http://dx.doi.org/10.55274/r0010601.
Повний текст джерелаАнотація:
Eddy current testing has received only limited application to ferrous materials because the high permeability of the material in combination with the normally high frequency of the eddy current instrument results in a very small depth of penetration of the eddy currents into the material. The objectives of this research program were threefold. The first goal was to develop an eddy current instrument with frequencies low enough to penetrate pipeline steel. The second was to use the new instrument to develop techniques for locating stress corrosion cracks (SCC) on coated pipelines without requiring the removal of the coating. Our last goal was to develop methods of characterizing SCC; i.e. determining the lengths and depths of the defects.
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Yan, Yujie, and Jerome F. Hajjar. Automated Damage Assessment and Structural Modeling of Bridges with Visual Sensing Technology. Northeastern University, May 2021. http://dx.doi.org/10.17760/d20410114.
Повний текст джерелаАнотація:
Recent advances in visual sensing technology have gained much attention in the field of bridge inspection and management. Coupled with advanced robotic systems, state-of-the-art visual sensors can be used to obtain accurate documentation of bridges without the need for any special equipment or traffic closure. The captured visual sensor data can be post-processed to gather meaningful information for the bridge structures and hence to support bridge inspection and management. However, state-of-the-practice data postprocessing approaches require substantial manual operations, which can be time-consuming and expensive. The main objective of this study is to develop methods and algorithms to automate the post-processing of the visual sensor data towards the extraction of three main categories of information: 1) object information such as object identity, shapes, and spatial relationships - a novel heuristic-based method is proposed to automate the detection and recognition of main structural elements of steel girder bridges in both terrestrial and unmanned aerial vehicle (UAV)-based laser scanning data. Domain knowledge on the geometric and topological constraints of the structural elements is modeled and utilized as heuristics to guide the search as well as to reject erroneous detection results. 2) structural damage information, such as damage locations and quantities - to support the assessment of damage associated with small deformations, an advanced crack assessment method is proposed to enable automated detection and quantification of concrete cracks in critical structural elements based on UAV-based visual sensor data. In terms of damage associated with large deformations, based on the surface normal-based method proposed in Guldur et al. (2014), a new algorithm is developed to enhance the robustness of damage assessment for structural elements with curved surfaces. 3) three-dimensional volumetric models - the object information extracted from the laser scanning data is exploited to create a complete geometric representation for each structural element. In addition, mesh generation algorithms are developed to automatically convert the geometric representations into conformal all-hexahedron finite element meshes, which can be finally assembled to create a finite element model of the entire bridge. To validate the effectiveness of the developed methods and algorithms, several field data collections have been conducted to collect both the visual sensor data and the physical measurements from experimental specimens and in-service bridges. The data were collected using both terrestrial laser scanners combined with images, and laser scanners and cameras mounted to unmanned aerial vehicles.
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Berney, Ernest, Naveen Ganesh, Andrew Ward, J. Newman, and John Rushing. Methodology for remote assessment of pavement distresses from point cloud analysis. Engineer Research and Development Center (U.S.), April 2021. http://dx.doi.org/10.21079/11681/40401.
Повний текст джерелаАнотація:
The ability to remotely assess road and airfield pavement condition is critical to dynamic basing, contingency deployment, convoy entry and sustainment, and post-attack reconnaissance. Current Army processes to evaluate surface condition are time-consuming and require Soldier presence. Recent developments in the area of photogrammetry and light detection and ranging (LiDAR) enable rapid generation of three-dimensional point cloud models of the pavement surface. Point clouds were generated from data collected on a series of asphalt, concrete, and unsurfaced pavements using ground- and aerial-based sensors. ERDC-developed algorithms automatically discretize the pavement surface into cross- and grid-based sections to identify physical surface distresses such as depressions, ruts, and cracks. Depressions can be sized from the point-to-point distances bounding each depression, and surface roughness is determined based on the point heights along a given cross section. Noted distresses are exported to a distress map file containing only the distress points and their locations for later visualization and quality control along with classification and quantification. Further research and automation into point cloud analysis is ongoing with the goal of enabling Soldiers with limited training the capability to rapidly assess pavement surface condition from a remote platform.