Thematische Bibliographien / Damage and detection

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Auswahl der wissenschaftlichen Literatur zum Thema „Damage and detection“

Autor: Grafiati

Veröffentlicht am 28. Juni 2021

Zuletzt aktualisiert am 1. Februar 2022

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Zeitschriftenartikel zum Thema "Damage and detection"

Vafaei, Mohammadreza, Azlan bin Adnan und Mohammadreza Yadollahi. „Seismic Damage Detection Using Pushover Analysis“. Advanced Materials Research 255-260 (Mai 2011): 2496–99. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.2496.

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Inter-story drift ratio is a general damage index which is being used to detect damaged stories after severe ground motions. Since this general damage index cannot detect damaged elements also the severity of imposed damages on elements, a new real-time seismic damage detection method base on artificial neural networks was proposed to overcome this issue. This approach considers nonlinear behaviour of structures and not only is capable of detecting damaged elements but also can address the severity of imposed damages. Proposed algorithm was applied on a 3-story concrete building .The obtained results confirmed accuracy and robustness of this method.

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Carminati, M., und S. Ricci. „Structural Damage Detection Using Nonlinear Vibrations“. International Journal of Aerospace Engineering 2018 (25.09.2018): 1–21. http://dx.doi.org/10.1155/2018/1901362.

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Nonlinear vibrations emerging from damaged structures are suitable indicators for detecting defects. When a crack arises, its behavior could be approximated like a bilinear stiffness. According to this scheme, typical nonlinear phenomena as the presence of superharmonics in the dynamic response and the variation of the oscillation frequency in time emerge. These physical consequences give the opportunity to study damage detection procedures with relevant improvements with respect to the typical strategies based on linear vibrations, such as high sensitivity to small damages, no need for an accurate comparison model, and behavior not influenced by environmental conditions. This paper presents a methodology, which aims at finding suitable nonlinear phenomena for the damage detection of three contact-type damages in a panel representing a typical aeronautical structural component. At first, structural simulations are executed using MSC Nastran models and reduced dynamic models in MATLAB in order to highlight relevant nonlinear behaviors. Then, proper experimental tests are developed in order to look for the nonlinear phenomena identified: presence of superharmonics in the dynamic response and nonlinear behavior of the lower frequency of vibration, computed using the CWT (continuous wavelet transform). The proposed approach exhibits the possibility to detect and localize contact-type damages present in a realistic assembled structure.

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Stoykov, Stanislav, Emil Manoach und Maosen Cao. „Vibration Based Damage Detection of Rotating Beams“. MATEC Web of Conferences 148 (2018): 14008. http://dx.doi.org/10.1051/matecconf/201814814008.

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The early detection and localization of damages is essential for operation, maintenance and cost of the structures. Because the frequency of vibration cannot be controlled in real-life structures, the methods for damage detection should work for wide range of frequencies. In the current work, the equation of motion of rotating beam is derived and presented and the damage is modelled by reduced thickness. Vibration based methods which use Poincaré maps are implemented for damage localization. It is shown that for clamped-free boundary conditions these methods are not always reliable and their success depends on the excitation frequency. The shapes of vibration of damaged and undamaged beams are shown and it is concluded that appropriate selection criteria should be defined for successful detection and localization of damages.

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Riddihough, G. „Damage Detection“. Science Signaling 1, Nr. 24 (17.06.2008): ec227-ec227. http://dx.doi.org/10.1126/scisignal.124ec227.

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Zhang, Yu, Xin Feng, Zhe Fan, Shuang Hou, Tong Zhu und Jing Zhou. „Experimental investigations on seismic damage monitoring of concrete dams using distributed lead zirconate titanate sensor network“. Advances in Structural Engineering 20, Nr. 2 (28.07.2016): 170–79. http://dx.doi.org/10.1177/1369433216660002.

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Seismic damage detection of concrete dams has always attracted much attention in hydraulic structure community. In this article, a novel seismic damage detection system was developed to perform seismic damage monitoring in concrete dams. As its importance in achieving the dam damage detection, the arrangement of a distributed lead zirconate titanate sensor network was introduced in detail. A dam model system with a distributed lead zirconate titanate sensor network was used as an object for verification. A shaking table was used to simulate the earthquake ground motion for the object to be tested. The seismic damage detection system could be used in not only the seismic damage process monitoring by measuring the dynamic stress history but also the distributed detecting of the dam damaged region. By analyzing the sensor signals, the emergence and development of the structural damages could be monitored timely. A damage index matrix was presented to evaluate the damage status of the dam in different paths. The experimental results verified the timeliness and the effectiveness of the proposed method.

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NASERALAVI, S. S., S. GERIST, E. SALAJEGHEH und J. SALAJEGHEH. „ELABORATE STRUCTURAL DAMAGE DETECTION USING AN IMPROVED GENETIC ALGORITHM AND MODAL DATA“. International Journal of Structural Stability and Dynamics 13, Nr. 06 (02.07.2013): 1350024. http://dx.doi.org/10.1142/s0219455413500247.

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This paper addresses a proficient strategy for detection of structural damages in details using the variations of eigenvalues and eigenvectors. There are two concerns in this study. First, the severity of damage can vary within the damaged elements; second, it is possible that the damage extents do not exactly match the pre-generated finite element mesh. The first concern forms the motivation for employing the proper damage functions to model the elemental damages, and the second for considering the nodal positions as design variables. To obtain the design variables, an improved genetic algorithm is introduced in which two new operators are embedded. This strategy is applied to a beam and a plate structure as the cases of study. The results demonstrate the applicability and efficiency of the proposed algorithm in elaborate damage detections.

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Park, Sang-Eun, und Yoon Taek Jung. „Detection of Earthquake-Induced Building Damages Using Polarimetric SAR Data“. Remote Sensing 12, Nr. 1 (01.01.2020): 137. http://dx.doi.org/10.3390/rs12010137.

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Remote sensing, particularly using synthetic aperture radar (SAR) systems, can be an effective tool in detecting and assessing the area and amount of building damages caused by earthquake or tsunami. Several studies have provided experimental evidence for the importance of polarimetric SAR observations in building damage detection and assessment, particularly caused by a tsunami. This study aims to evaluate the practical applicability of the polarimetric SAR observations to building damage caused by the direct ground-shaking of an earthquake. The urban areas heavily damaged by the 2016 Kumamoto earthquake in Japan have been investigated by using the polarimetric PALSAR-2 data acquired in pre- and post-earthquake conditions. Several polarimetric change detection approaches, such as the changes of polarimetric scattering powers, the matrix dissimilarity measures, and changes of the radar scattering mechanisms, were examined. Optimal damage indicators in the presence of significant natural changes, and a novel change detection method by the fuzzy-based fusion of polarimetric damage indicators are proposed. The accuracy analysis results show that the proposed automatic classification method can successfully detect the selected damaged areas with a detection rate of 90.9% and false-alarm rate of 1.3%.

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Duarte, D., F. Nex, N. Kerle und G. Vosselman. „DAMAGE DETECTION ON BUILDING FAÇADES USING MULTI-TEMPORAL AERIAL OBLIQUE IMAGERY“. ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2/W5 (29.05.2019): 29–36. http://dx.doi.org/10.5194/isprs-annals-iv-2-w5-29-2019.

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<p><strong>Abstract.</strong> Over the past decades, a special interest has been given to remote-sensing imagery to automate the detection of damaged buildings. Given the large areas it may cover and the possibility of automation of the damage detection process, when comparing with lengthy and costly ground observations. Currently, most image-based damage detection approaches rely on Convolutional Neural Networks (CNN). These are used to determine if a given image patch shows damage or not in a binary classification approach. However, such approaches are often trained using image samples containing only debris and rubble piles. Since such approaches often aim at detecting partial or totally collapsed buildings from remote-sensing imagery. Hence, such approaches might not be applicable when the aim is to detect façade damages. This is due to the fact that façade damages also include spalling, cracks and other small signs of damage. Only a few studies focus their damage analysis on the façade and a multi-temporal approach is still missing. In this paper, a multi-temporal approach specifically designed for the image classification of façade damages is presented. To this end, three multi-temporal approaches are compared with two mono-temporal approaches. Regarding the multi-temporal approaches the objective is to understand the optimal fusion between the two imagery epochs within a CNN. The results show that the multi-temporal approaches outperform the mono-temporal ones by up to 22% in accuracy.</p>

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Titurus, Branislav, Michael I. Friswell und Ladislav Starek. „Damage detection using generic elements: Part II. Damage detection“. Computers & Structures 81, Nr. 24-25 (September 2003): 2287–99. http://dx.doi.org/10.1016/s0045-7949(03)00318-3.

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Huang, Ming-Chih, Yen-Po Wang und Ming-Lian Chang. „Damage Detection of Structures Identified with Deterministic-Stochastic Models Using Seismic Data“. Scientific World Journal 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/879341.

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A deterministic-stochastic subspace identification method is adopted and experimentally verified in this study to identify the equivalent single-input-multiple-output system parameters of the discrete-time state equation. The method of damage locating vector (DLV) is then considered for damage detection. A series of shaking table tests using a five-storey steel frame has been conducted. Both single and multiple damage conditions at various locations have been considered. In the system identification analysis, either full or partial observation conditions have been taken into account. It has been shown that the damaged stories can be identified from global responses of the structure to earthquakes if sufficiently observed. In addition to detecting damage(s) with respect to the intact structure, identification of new or extended damages of the as-damaged counterpart has also been studied. This study gives further insights into the scheme in terms of effectiveness, robustness, and limitation for damage localization of frame systems.

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Dissertationen zum Thema "Damage and detection"

Cockerill, Aaron. „Damage detection of rotating machinery“. Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/105671/.

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Acoustic emission (AE) is an emerging technique for the condition monitoring of rotating machinery components, including both rolling element bearings and gears. Due to the high frequency range over which AE is sensitive to, AE potentially offers advantages for detection of incipient damage at an early stage of failure when compared to traditional techniques such as vibration. This thesis first investigates the effects of increased speed and load on the generation of AE within cylindrical roller bearings, and determines similarities and differences between AE and vibrational data. A traditional AE sensor was used in conjunction with a Dual Function Sensor (DFS) capable of recording both low frequency AE and vibration. It was shown that increasing speed has the greatest influence on the AE signals produced whereas the effect of load was limited. Order analysis of both AE and vibrational data also demonstrated that characteristic bearing defect frequencies are visible in the AE spectrum but not in the vibrational spectrum. Bearings with seeded defects upon the outer raceway were investigated under a fixed speed and it was found that load increased the energy within the signal frequency spectrum as the damaged increased. Two bearing life tests were also conducted, one accelerated to 12 hours and the second extended to over 2800 hours however as damage detection only occurred after significant damage had developed, it is concluded that AE of seeded defects indicate a false sensitivity. Both life tests were able to demonstrate that signal levels increase as damage propagates over the bearing raceway however it was not possible to determine any advantage of using AE over vibration. AE sensors were also applied to test rigs of increased complexity, including the monitoring a wind turbine planet bearing and a helical gear pair. AE was able to detect cracking of the shaft surface within the wind turbine bearing test rig which was mistaken for being an inner raceway failure, highlighting the difficulty in damage location. A tooth failure occurred during the testing of the helical gear pair however AE was not able to detect growing damage, instead only increasing in amplitude after the tooth had sheared off, similar to the detection from vibrational signals.

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Al, Jailawi Samer Saadi Hussein. „Damage detection using angular velocity“. Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6539.

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The present work introduces novel methodologies for damage detection and health monitoring of structural and mechanical systems. The new approach uses the angular velocity inside different mathematical forms, via a gyroscope, to detect, locate, and relatively quantify damage. This new approach has been shown to outperform the current state-of-the-art acceleration-based approach in detecting damage on structures. Additionally, the current approach has been shown to be less sensitive to environmental acoustic noises, which present major challenges to the acceleration-based approaches. Furthermore, the current approach has been demonstrated to work effectively on arch structures, which acceleration-based approaches have struggled to deal with. The efficacy of the new approach has been investigated through multiple forms of structural damage indices. The first methodology proposed a damage index that is based on the changes in the second spatial derivative (curvature) of the power spectral density (PSD) of the angular velocity during vibration. The proposed method is based on the output motion only and does not require information about the input forces/motions. The PSD of the angular velocity signal at different locations on structural beams was used to identify the frequencies where the beams show large magnitude of angular velocity. The curvature of the PSD of the angular velocity at these peak frequencies was then calculated. A damage index is presented that measures the differences between the PSD curvature of the angular velocity of a damaged structure and an artificial healthy baseline structure. The second methodology proposed a damage index that is used to detect and locate damage on straight and curved beams. The approach introduces the transmissibility and coherence functions of the output angular velocity between two points on a structure where damage may occur to calculate a damage index as a metric of the changes in the dynamic integrity of the structure. The damage index considers limited-frequency bands of the transmissibility function at frequencies where the coherence is high. The efficacy of the proposed angular-velocity damage-detection approach as compared to the traditional linear-acceleration damage-detection approach was tested on straight and curved beams with different chord heights. Numerical results showed the effectiveness of the angular-velocity approach in detecting damage of multiple levels. It was observed that the magnitude of the damage index increased with the magnitude of damage, indicating the sensitivity of the proposed method to damage intensity. The results on straight and curved beams showed that the proposed approach is superior to the linear-acceleration-based approach, especially when dealing with curved beams with increasing chord heights. The experimental results showed that the damage index of the angular-velocity approach outweighed that of the acceleration approach by multiple levels in terms of detecting damage. A third methodology for health-monitoring and updating of structure supports, which resemble bridges’ bearings, is introduced in this work. The proposed method models the resistance of the supports as rotational springs and uses the transmissibility and coherence functions of the output response of the angular velocity in the neighborhood of the bearings to detect changes in the support conditions. The proposed methodology generates a health-monitoring index that evaluates the level of deterioration in the support and a support-updating scheme to update the stiffness resistance of the supports. Numerical and experimental examples using beams with different support conditions are introduced to demonstrate the effectiveness of the proposed method. The results show that the proposed method detected changes in the state of the bearings and successfully updated the changes in the stiffness of the supports.

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Dissanayake, Amal S. „Electrostatic discharge damage detection method“. Thesis, Kansas State University, 1997. http://hdl.handle.net/2097/13512.

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Gharibnezhad, Fahit. „Robust damage detection in smart structures“. Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/277544.

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This thesis is devoted to present some novel techniques in Structural Health Monitoring (SHM). SHM is a developing field that tries to monitor structures to make sure that they remain in their desired condition to avoid any catastrophe. SHM includes different levels from damage detection area to prognosis field. This work is dedicated to the first level, which might be considered the main and most important level. New techniques presented in this work are based on different statistical and signal processing methods such as Principal Component Analysis and its robust counterpart, Wavelet Transform, Fuzzy similarity, Andrew plots, etc. These techniques are applied on the propagated waves that are activated and captured in the structure using appropriate transducers. Piezoceramic (PZT) devices are chosen in this work to capture the signals due to their special characteristics such as high performance, low energy consumption and reasonable price. To guarantee the efficiency of the suggested techniques, they are tested on different laboratory and real scale test benchmarks, such as aluminum and composite plates, fuselage, wing skeleton, tube, etc. Because of the variety of tested benchmarks, this thesis is called damage detection in smart structures. This variety may promise the ability and capability of the proposed methods on different fields such as aerospace and gas/oil industry. In addition to the normal laboratory conditions, it is shown in this work that environmental changes can affect the performance of the damage detection and wave propagation significantly. As such, there is a vital need to consider their effect. In this work, temperature change is chosen as it is one of the main environmental fluctuation factors. To scrutinize its effect on damage detection, first, the effect of temperature is considered on wave propagation and then all the proposed methods are tested to check whether they are sensitive to temperature change or not. Finally, a temperature compensation method is applied to ensure that the proposed methods are stable and robust even when structures are subjected to variant environmental conditions.
La presente tesis doctoral se dedica a la exploración y presentación de técnicas novedosas para la Monitorización y detección de defectos en estructuras (Structural Health Monitoring -SHM-) SHM es un campo actualmente en desarrollo que pretende asegurarse que las estructuras permanecen en su condición deseada para evitar cualquier catástrofe. En SHM se presentan diferentes niveles de diagnóstico, Este trabajo se concentra en el primer nivel, que se considera el más importante, la detección de los defectos. Las nuevas técnicas presentadas en esta tesis se basan en diferentes métodos estadísticos y de procesamiento de señales tales como el Análisis de Componentes Princpales (PCA) y sus variaciones robustas, Transformada wavelets, lógica difusa, gráficas de Andrew, etc. Estas técnicas de aplican sobre las ondas de vibración que se generan y se miden en la estructura utilizando trasductores apropiados. Dispositivos piezocerámicos (PZT's) se han escogido para este trabajo ya que presentan características especiales tales como: alto rendimiento, bajo consumo de energia y bajo costo. Para garantizar la eficacia de la metodología propuesta,se ha validado en diferentes laboratorios y estructuras a escala real: placas de aluminio y de material compuesto, fuselage de un avión, revestimiento del ala de un avóin, tubería, etc. Debido a la gran variedad de estructuras utilizadas, su aplicación en la industria aeroespacial y/o petrolera es prometedora. Por otra parte, los cambios ambientales pueden afectar al rendimiento de la detección de daños y propagación de la onda significativamente . En este trabajo , se estudia el efecto de las variaciones de temperatura ya que es uno de los principales factores de fluctuación del medio ambiente . Para examinar su efecto en la detección de daños, en primer lugar, todos los métodos propuestos se prueban para comprobar si son sensibles a los cambios de temperatura o no. Finalmente , se aplica un método de compensación de temperatura para garantizar que los métodos propuestos son estables y robustos incluso cuando las estructuras se someten a condiciones ambientales variantes

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Matlack, Kathryn H. „Nonlinear ultrasound for radiation damage detection“. Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51965.

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Radiation damage occurs in reactor pressure vessel (RPV) steel, causing microstructural changes such as point defect clusters, interstitial loops, vacancy-solute clusters, and precipitates, that cause material embrittlement. Radiation damage is a crucial concern in the nuclear industry since many nuclear plants throughout the US are entering the first period of life extension and older plants are currently undergoing assessment of technical basis to operate beyond 60 years. The result of extended operation is that the RPV and other components will be exposed to higher levels of neutron radiation than they were originally designed to withstand. There is currently no nondestructive evaluation technique that can unambiguously assess the amount of radiation damage in RPV steels. Nonlinear ultrasound (NLU) is a nondestructive evaluation technique that is sensitive to microstructural features such as dislocations, precipitates, and their interactions in metallic materials. The physical effect monitored by NLU is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave, arising from the interaction of the ultrasonic wave with microstructural features. This effect is quantified with the measurable acoustic nonlinearity parameter, beta. In this work, nonlinear ultrasound is used to characterize radiation damage in reactor pressure vessel steels over a range of fluence levels, irradiation temperatures, and material composition. Experimental results are presented and interpreted with newly developed analytical models that combine different irradiation-induced microstructural contributions to the acoustic nonlinearity parameter.

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Huethwohl, Philipp Karl. „Bridge damage detection and BIM mapping“. Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/285562.

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Bridges are a vitally important part of modern infrastructure. Their condition needs to be monitored on a continuous basis in order to ensure their safety and functionality. Teams of engineers visually inspect more than half a million bridges per year in the US and the EU. There is clear evidence to suggest that they are not able to meet all bridge inspection guideline requirements. In addition, the format and storage of inspection reports varies considerably across authorities because of the lack of standardisation. The availability of a comprehensive and open digital representation of the data involved in and required for bridge inspection is an indispensable necessity for exploiting the full potential of modern digital technologies like big data exploration, artificial intelligence and database technologies. A thorough understanding of bridge inspection information requirements for reinforced concrete bridges is needed as basis for overcoming the stated problem. This work starts with a bridge inspection guideline analysis, from which an information model and a candidate binding to Industry Foundation Classes (IFC) is developed. The resulting bridge model can fully store inspection information in a standardised way which makes it easily shareable and comparable between users and standards. Then, two inspection stages for locating and classifying visual concrete defects are devised, implemented and benchmarked to support the bridge inspection process: In a first stage, healthy concrete surfaces are located and disregarded for further inspection. In a second hierarchical classification stage, each of the remaining potentially unhealthy surface areas is classified into a specific defect type in accordance with bridge inspection guidelines. The first stage achieves a search space reduction for a subsequent defect type classification of over 90% with a risk of missing a defect patch of less than 10%. The second stage identifies the correct defect type to a potentially unhealthy surface area with a probability of 85%. A prototypical implementation serves as a proof of concept. This work closes the gap between requirements arising from established inspection guidelines, the demand for holistic data models which has recently become known as "digital twin", and methods for automatically identifying and measuring specific defect classes on small scale images. It is of great significance for bridge inspectors, bridge owners and authorities as they now have more suitable data models at hand to store, view and manage maintenance information on bridges including defect location and defect types which are being retrieved automatically. With these developments, a foundation is available for a complete revision of bridge inspection processes on a modern, digital basis.

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Malik, Shoaib Ahmad. „Damage detection using self-sensing composites“. Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1750/.

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The primary aim of this research programme was to enable damage detection in glass fibre reinforced composites using the reinforcing fibres as the sensing element. In other words, E-glass fibres were used as light guides to detect the fracture of individual fibres, when loaded in tension. This was achieved by monitoring the transmitted light intensity through the reinforcing glass fibres. Two types of glass fibres and matrices were evaluated. In the case of glass fibres, E-glass and custom-made small-diameter (12 µm) optical fibre (SDOF) were used. Three types of low refractive index resin systems with specified failure strains were also used. The basic technology involved illuminating one end of the fibre bundle or composite with a white light or laser source and the opposite end was imaged using a high-speed CCD camera. Acoustic emission monitoring of fibre bundles revealed that there were two types of failures occurring in a bundle, a lower amplitude of the acoustic emission signal (AES) related to the inter-fibre friction and a high amplitude of the AES to fibre fractures. This characteristic was also confirmed by a Weibull statistical analysis where it was demonstrated that a two parameter distribution was present corresponding to two different flaw distributions. In the case of self-sensing composites, it was found that the specific failure modes in the composites (matrix failure, fibre fracture, debonding) generate their characteristic amplitudes of the AES and frequencies. These failure modes were recorded and correlated to the tensile test data. It was demonstrated that the attenuation of transmitted light can be related to the fracture of fibres in the bundle or a composite test specimen. It was found that the image analysis routines were capable of identifying and tracking the survival or fracture of each fibre in the bundle or composite. The results obtained from mechanical loading, acoustic emission and images analysis were cross-correlated.

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Asnaashari, Erfan. „Vibration-based damage detection in structures“. Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/vibrationbased-damage-detection-in-structures(09061582-55fb-4fba-846e-2156dd4ef172).html.

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Structural health monitoring systems have a great potential for cost saving and safety improvement in different types of structures. One of the most important tasks of these systems is to identify damage at an early stage of its development. A variety of methods may be used to identify, locate, or quantify the extent of damage or fault in a structural or mechanical component. However, the preferable method is the one which maximises the probability of detecting the flaw, while also considering feasibility of in-situ testing, ease of use and economic factors. Cracks are one of the common defects in structural components that may ultimately lead to failure of structures if not detected. The presence of cracks in a structure brings about local variations in the stiffness of the structure. These variations cause the dynamic behaviour of the cracked structure to be different from that of a healthy one. Vibration-based damage detection methods have attracted considerable attention over the past few decades. These methods generally use changes to the physical properties of structures for the purpose of crack detection. In this thesis, two new vibration-based methods have been developed for damage detection in beam-like and rotor-type structures. The first method performs the entire signal processing required for crack detection in time domain. It is based on assessing the normality of vibration responses using the normal probability plot (NPP). The amount of deviation between the actual and normal distribution of measured vibration responses was calculated along the length of the structure to localise the crack. The second proposed method converts the vibration responses into frequency domain for further processing. Excitation of the cracked structure at a given frequency always generates higher harmonic components of the exciting frequency due to the breathing of the crack. This method uses the operational deflection shape of the structure at the exciting frequency and its higher harmonics to identify the crack location. Avoiding complicated signal processing in frequency domain is the main advantage of the first method. However, more precise identification of crack locations can be obtained through the second method. Generally, both methods have the advantage of being easy, reference-free and applicable to in-situ testing for any structure. The concept and computational approach of both methods along with their validations through numerical and experimental examples have been presented. Moreover, different input excitations have been used to evaluate the capability of the developed methods in detecting the crack location(s).

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Tadros, Nader Nabil Aziz. „Structural damage detection using ambient vibrations“. Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/18178.

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Master of Science
Department of Civil Engineering
Hani G. Melhem
The objective of this research is to use structure ambient random vibration response to detect damage level and location. The use of ambient vibration is advantageous because excitation is caused by service conditions such as normal vehicle traffic on a highway bridge, train passage on a railroad bridge, or wind loads on a tall building. This eliminates the need to apply a special impact or dynamic load, or interrupt traffic on a bridge in regular service. This research developed an approach in which free vibration of a structure is extracted from the response of this structure to a random excitation in the time domain (acceleration versus time) by averaging out the random component of the response. The result is the free vibration that includes all modes based on the sampling rate on time. Then this free vibration is transferred to the frequency domain using a Fast Fourier Transform (FFT). Variations in frequency response are a function of structural stiffness and member end-conditions. Such variations are used as a measure to identify the change in the structural dynamic properties, and ultimately detect damage. A physical model consisting of a 20 × 20 × 1670 -mm long steel square tube was used to validate this approach. The beam was tested under difference supports conditions varying from a single- to three-span continuous configuration. Random excitation was applied to the beam, and the dynamic response was measured by an accelerometer placed at various locations on the span. A numerical model was constructed in ABAQUS and the dynamic response was obtained from the finite element model subjected to similar excitation as in the physical model. Numerical results were correlated against results from the physical model, and comparison was made between the different span/support configurations. A subsequent step would be to induce damage that simulates loss of stiffness or cracking condition of the beam cross section, and that would be reflected as a change in the frequency and other dynamic properties of the structure. The approach achieved good results for a structure with a limited number of degrees of freedom. Further research is needed for structures with a larger number of degrees of freedom and structures with damage in symmetrical locations relative to the accelerometer position.

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Dixit, Akash. „Damage modeling and damage detection for structures using a perturbation method“. Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43575.

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This thesis is about using structural-dynamics based methods to address the existing challenges in the field of Structural Health Monitoring (SHM). Particularly, new structural-dynamics based methods are presented, to model areas of damage, to do damage diagnosis and to estimate and predict the sensitivity of structural vibration properties like natural frequencies to the presence of damage. Towards these objectives, a general analytical procedure, which yields nth-order expressions governing mode shapes and natural frequencies and for damaged elastic structures such as rods, beams, plates and shells of any shape is presented. Features of the procedure include the following: 1. Rather than modeling the damage as a fictitious elastic element or localized or global change in constitutive properties, it is modeled in a mathematically rigorous manner as a geometric discontinuity. 2. The inertia effect (kinetic energy), which, unlike the stiffness effect (strain energy), of the damage has been neglected by researchers, is included in it. 3. The framework is generic and is applicable to wide variety of engineering structures of different shapes with arbitrary boundary conditions which constitute self adjoint systems and also to a wide variety of damage profiles and even multiple areas of damage. To illustrate the ability of the procedure to effectively model the damage, it is applied to beams using Euler-Bernoulli and Timoshenko theories and to plates using Kirchhoff's theory, supported on different types of boundary conditions. Analytical results are compared with experiments using piezoelectric actuators and non-contact Laser-Doppler Vibrometer sensors. Next, the step of damage diagnosis is approached. Damage diagnosis is done using two methodologies. One, the modes and natural frequencies that are determined are used to formulate analytical expressions for a strain energy based damage index. Two, a new damage detection parameter are identified. Assuming the damaged structure to be a linear system, the response is expressed as the summation of the responses of the corresponding undamaged structure and the response (negative response) of the damage alone. If the second part of the response is isolated, it forms what can be regarded as the damage signature. The damage signature gives a clear indication of the damage. In this thesis, the existence of the damage signature is investigated when the damaged structure is excited at one of its natural frequencies and therefore it is called ``partial mode contribution". The second damage detection method is based on this new physical parameter as determined using the partial mode contribution. The physical reasoning is verified analytically, thereupon it is verified using finite element models and experiments. The limits of damage size that can be determined using the method are also investigated. There is no requirement of having a baseline data with this damage detection method. Since the partial mode contribution is a local parameter, it is thus very sensitive to the presence of damage. The parameter is also shown to be not affected by noise in the detection ambience.

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Bücher zum Thema "Damage and detection"

Didenko, Vladimir V., Hrsg. Fast Detection of DNA Damage. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-7187-9.

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Masters, JE, Hrsg. Damage Detection in Composite Materials. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 1992. http://dx.doi.org/10.1520/stp1128-eb.

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Baruch, Menahem. Damage detection based on reduced measurements. [Haifa]: Technion-Israel Institute of Technology, Faculty of Aerospace Engineering, 1995.

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Decker, Arthur J. Damage detection using holography and interferometry. Cleveland, Ohio: National Aeronautics and Space Administration, Glenn Research Center, 2003.

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Eftekhar Azam, Saeed. Online Damage Detection in Structural Systems. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-02559-9.

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Didenko, Vladimir V. In Situ Detection of DNA Damage. New Jersey: Humana Press, 2002. http://dx.doi.org/10.1385/1592591795.

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Mahall, Karl. Quality assessment of textiles: Damage detection bymicroscopy. Berlin: Springer-Verlag, 1993.

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Morassi, Antonino, und Fabrizio Vestroni, Hrsg. Dynamic Methods for Damage Detection in Structures. Vienna: Springer Vienna, 2008. http://dx.doi.org/10.1007/978-3-211-78777-9.

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Mahall, Karl. Quality assessment of textiles: Damage detection by microscopy. Berlin: Springer-Verlag, 1993.

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Mahall, Karl. Quality Assessment of Textiles: Damage Detection by Microscopy. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003.

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Buchteile zum Thema "Damage and detection"

Frangopol, Dan M., und Sunyong Kim. „Probabilistic Damage Detection“. In Life-Cycle of Structures Under Uncertainty, 51–71. Boca Raton, FL : CRC Press, 2019. | “A science publishers book.”: CRC Press, 2019. http://dx.doi.org/10.1201/9780429053283-3.

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Xu, You-Lin, und Jia He. „Structural damage detection“. In Smart Civil Structures, 333–88. Boca Raton : Taylor & Francis, CRC Press, 2017.: CRC Press, 2017. http://dx.doi.org/10.1201/9781315368917-15.

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Ghosh, Bidisha, Michael O’Byrne, Franck Schoefs und Vikram Pakrashi. „Surface damage detection“. In Image-Based Damage Assessment for Underwater Inspections, 97–126. Boca Raton : Taylor & Francis, a CRC title, part of the Taylor & Francis imprint, a member of the Taylor & Francis Group, the academic division of T&F Informa, plc, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9781351052580-6.

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Hirao, Masahiko, und Hirotsugu Ogi. „Creep Damage Detection“. In Electromagnetic Acoustic Transducers, 337–45. Tokyo: Springer Japan, 2016. http://dx.doi.org/10.1007/978-4-431-56036-4_17.

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Limongelli, Maria Pina, Emil Manoach, Said Quqa, Pier Francesco Giordano, Basuraj Bhowmik, Vikram Pakrashi und Alfredo Cigada. „Vibration Response-Based Damage Detection“. In Structural Health Monitoring Damage Detection Systems for Aerospace, 133–73. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72192-3_6.

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AbstractThis chapter aimed to present different data driven Vibration-Based Methods (VBMs) for Structural Health Monitoring (SHM). This family of methods, widely used for engineering applications, present several advantages for damage identification applications. First, VBMs provide continuous information on the health state of the structure at a global level without the need to access the damaged elements and to know their location. Furthermore, damage can be identified using the dynamic response of the structure measured by sensors non-necessarily located in the proximity of damage and without any prior knowledge about the damage location. By principle, VBMs can identify damage related to changes in the dynamic properties of structures, such as stiffness variations due to modifications in the connections between structural elements, or changes in geometric and material properties. A classification of different VBMs was presented in this chapter. Furthermore, several case studies were presented to demonstrate the potential of these methods.

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Uhl, Tadeusz, Tadeusz Stepinski und Wieslaw Staszewski. „Introduction“. In Advanced Structural Damage Detection, 1–15. Chichester, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118536148.ch1.

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Kohut, Piotr, und Krzysztof Holak. „Vision-Based Monitoring System“. In Advanced Structural Damage Detection, 279–320. Chichester, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118536148.ch10.

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Paćko, Paweł. „Numerical Simulation of Elastic Wave Propagation“. In Advanced Structural Damage Detection, 17–56. Chichester, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118536148.ch2.

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Gallina, Alberto, Paweł Paćko und Łukasz Ambroziński. „Model Assisted Probability of Detection in Structural Health Monitoring“. In Advanced Structural Damage Detection, 57–72. Chichester, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118536148.ch3.

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Klepka, Andrzej. „Nonlinear Acoustics“. In Advanced Structural Damage Detection, 73–107. Chichester, UK: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118536148.ch4.

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Konferenzberichte zum Thema "Damage and detection"

Gawronski, Wodek, und Jerzy T. Sawicki. „Structural Damage Detection Using Modal Norms“. In ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8374.

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Abstract A modal H2 norm is used to detect structural damages. The norm is determined for each sensor location, and for modal modes of interest. The sensor norm detects the damage location, the modal norm detect the most damaged mode.

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Ghazi, Reza Mohammadi, James Long und Oral Buyukozturk. „Structural Damage Detection Based on Energy Transfer Between Intrinsic Modes“. In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3022.

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In this study, a new damage detection algorithm for specific types of damages such as breathing cracks, which are called “active discontinuities” in this paper, is proposed. The algorithm is based on the nonlinear behavior of this class of damages and hence, is more precise and sensitive to damage compared to other common linear methods. The active discontinuities can be regarded as additional degrees of freedom (DOFs) which need energy to be excited. Because the input energy of both the intact and the damaged structures is finite, the energy content of vibrating modes will be changed due to damage. Thus, the properties of distribution of energy between vibrating modes can be used as indices for detecting damage. An essential detectability condition using this concept is decomposing a signal such that no spurious mode imposed to its expansion. In order to satisfy this condition, Empirical Mode decomposition (EMD) is used to extract the vibrating modes since all nonlinearities in a signal are preserved while no spurious mode or assumption of stationarity is imposed on the problem. Prevention of mode mixing, which is an important drawback of EMD, is another necessary condition for robustness of the algorithm. A solution is proposed in this paper to satisfy this condition in which special constraints are imposed on the normal procedure of EMD. Then, the fourth central moment, kurtosis, is used to compare the distribution of energy between the modified vibrating modes. The algorithm is verified through experimental testing of a simple steel cantilever structure under various damage scenarios. Results demonstrate the efficacy of the method for detecting discontinuities in a real structure.

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Myers, Oliver J., und Sourav Banerjee. „Coupled Damage Precursor Detection“. In ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/smasis2015-8950.

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This conceptual research focuses on identifying damage precursors in carbon fiber reinforced polymer laminates. By coupling integrated in situ sensing elements (magnetostrictive particles) and multi-scale ultrasonic inspection (Quantitative Ultrasonic Imaging) with minimum hardware the authors are able to capture and gain an understanding of damage precursors. Preliminary damage precursors can be identified and quantified and correlated to a particular failure mode(s) and/or fabrication process accelerating the need for a sensing/repair strategy that could be implemented to capture the specific precursor prior to the onset of cracks. Capturing and mitigating damage precursors ahead of micro-crack formulation will slow the evolution of the damage precursors to micro-cracks, mitigate adverse loading environment, and develop techniques to reduce stress and loading below the endurance limit to keep it from being fatigued.

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Wimmer, Stephanie A., und Virginia G. DeGiorgi. „Damage detection using wavelets“. In NDE for Health Monitoring and Diagnostics, herausgegeben von Tribikram Kundu. SPIE, 2003. http://dx.doi.org/10.1117/12.483820.

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Zhong, Shuncong, und S. Olutunde Oyadiji. „Wavelet-Based Structural Damage Detection“. In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35632.

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In this paper, a new wavelet-based approach for crack identification in beam-like structures is presented and applied to simply-supported beams with single or multiple cracks. A novel damage index, based on finding the difference between two sets of detail coefficients obtained by the use of the Stationary Wavelet Transform (SWT) of two reconstructed sets of modal displacement data of the cracked beam-like structure, is proposed for single crack detection or multiple crack detection. These two sets of mode shape data represent the left half and the modified right half of the modal data of the structure. Currently, SWT is widely used in the field of image processing for image noise reduction and image quality improvement. However, because it can provide an accurate estimate of the variances at each scale and facilitate the identification of salient features in a signal, SWT has great potential in the field of structural damage detection. In this paper, the modal responses of the damaged simply supported beams used are computed using the finite element method (FEM). The modal data generate is decomposed by SWT into a smooth curve, called approximation coefficient, and detail coefficient. It is shown that the detail coefficient includes crack information that is useful for structural damage detection. Therefore, a novel damage index, the difference of the SWT detail coefficients of two reconstructed sets of modal displacement data, is proposed and employed. The numerical simulation results show that the proposed wavelet-based method has a good anti-noise ability and it does not require the modal parameters of an intact structure as a baseline for crack detection. Therefore, it can be recommended for real applications in structural health monitoring and damage detection.

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Feng, Wei, Qiaofeng Li und Qiuhai Lu. „A Hierarchical Bayesian Method for Time Domain Structure Damage Detection“. In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-97026.

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Abstract A time domain structural damage detection method based on hierarchical Bayesian framework is proposed. Due to local stiffness reductions, the responses of damaged structures vary from those in undamaged status under the same external excitation. In this paper, the responses of damaged structures are assumed as the result of a summation of known external forces and unknown virtual forces exerted on corresponding undamaged structures. The damages can thus be detected, located, and quantified by the identification of associated virtual forces. A hierarchical Bayesian formulation considering all undetermined damage-related variables is adopted for the identification of virtual forces. The reasonable values of the variables and their uncertainties are depicted by their posterior distributions, sampled by Markov chain Monte Carlo method. Compared with traditional Bayesian formulations, manual choice of prior parameters is avoided and less prior information is required. The proposed virtual force indicator provides a more intuitive perspective for damage detection tasks and is potentially more operable in engineering practice. These advantages are illustrated by simulation of a cantilever beam under various damage conditions.

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Douti, Dam-Bé L., Sherazade Aknoun, Serge Monneret, Christophe Hecquet, Mireille Commandré und Laurent Gallais. „In-line quantitative phase imaging for damage detection and analysis“. In SPIE Laser Damage, herausgegeben von Gregory J. Exarhos, Vitaly E. Gruzdev, Joseph A. Menapace, Detlev Ristau und MJ Soileau. SPIE, 2014. http://dx.doi.org/10.1117/12.2068178.

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Medici, Ezequiel, Andres Cecchini, David Serrano und Frederick Just. „Damage Detection in Composite Beam Using the Temperature Distribution“. In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-16073.

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Marine, aerospace, ground and civil structures can receive unexpected loading that may compromise integrity during their life span. Therefore, improvement in detecting damage can save revenue and lives depending upon the application. The prognostic capability is usually a function of the examiner's experience, background and data collection during the evaluation. Nondestructive evaluation (NDE) methods are varied and specific to a given type of system (material, damage type, loading and environmental scenarios). As a result, one method of damage detection alone cannot examine all possible conditions and may even give false readings. This work examined the transient thermal response technique to assess damage in a sandwich composite structure. The mathematical formulation of the problem is presented. Then, a numerical approximation technique is used to solve the governing equations. The thermal distribution on the surface of a beam model is analyzed when damage is introduced. Then, an experimental setup with an Infrared (IR) thermography camera was assembled in order to provide the necessary information about the surface temperature distribution over the beam. Several damages scenarios will be tested by the technique with the purpose of determining the limitations of the method. The obtained experimental data was used to validate the numerical model. Finally, the feasibility of this feature to use in damage detection is discussed.

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Soni, Sunilkumar, Santanu Das und Aditi Chattopadhyay. „Optimal Sensor Placement for Damage Detection in Complex Structures“. In ASME 2009 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2009. http://dx.doi.org/10.1115/smasis2009-1419.

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An optimal sensor placement methodology is proposed based on detection theory framework to maximize the detection rate and minimize the false alarm rate. Minimizing the false alarm rate for a given detection rate plays an important role in improving the efficiency of a Structural Health Monitoring (SHM) system as it reduces the number of false alarms. The placement technique is such that the sensor features are as directly correlated and as sensitive to damage as possible. The technique accounts for a number of factors, like actuation frequency and strength, minimum damage size, damage detection scheme, material damping, signal to noise ratio (SNR) and sensing radius. These factors are not independent and affect each other. Optimal sensor placement is done in two steps. First, a sensing radius, which can capture any detectable change caused by a perturbation and above a certain threshold, is calculated. This threshold value is based on Neyman-Pearson detector that maximizes the detection rate for a fixed false alarm rate. To avoid sensor redundancy, a criterion to minimize sensing region overlaps of neighboring sensors is defined. Based on the sensing region and the minimum overlap concept, number of sensors needed on a structural component is calculated. In the second step, a damage distribution pattern, known as probability of failure distribute, is calculated for a structural component using finite element analysis. This failure distribution helps in selecting the most sensitive sensors, thereby removing those making remote contributions to the overall detection scheme.

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Adachi, Yukio, Shigeki Unjoh, Masuo Kondoh und Michio Ohsumi. „Nondestructive damage detection and evaluation technique for seismically damaged structures“. In Nondestructive Evaluation Techniques for Aging Infrastructures & Manufacturing, herausgegeben von Steven B. Chase. SPIE, 1999. http://dx.doi.org/10.1117/12.339935.

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Berichte der Organisationen zum Thema "Damage and detection"

Farrar, Charles R., Keith Worden, Michael D. Todd, Gyuhae Park, Jonathon Nichols, Douglas E. Adams, Matthew T. Bement und Kevin Farinholt. Nonlinear System Identification for Damage Detection. Office of Scientific and Technical Information (OSTI), November 2007. http://dx.doi.org/10.2172/922532.

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Miller, Tim, und R. Lasser. Composite Damage Detection Using Novel Experimental Methods. Fort Belvoir, VA: Defense Technical Information Center, September 2002. http://dx.doi.org/10.21236/ada407271.

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Hartman, George A. Infrared Damage Detection System (IDDS) for Real-Time, Small-Scale Damage Monitoring. Fort Belvoir, VA: Defense Technical Information Center, Januar 2007. http://dx.doi.org/10.21236/ada467885.

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Miller, T. C., Bob Lasser und Burt VanderHeiden. Composite Damage Detection Using a Novel Ultrasonic Method. Fort Belvoir, VA: Defense Technical Information Center, Januar 2003. http://dx.doi.org/10.21236/ada410224.

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Haworth, W. L. Fatigue Damage Detection in Steels by Optical Correlation. Fort Belvoir, VA: Defense Technical Information Center, März 1985. http://dx.doi.org/10.21236/ada155830.

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Mishra, Pranay, Asha Hall und Michael Coatney. Embedded Carbon Nanotube Networks for Damage Precursor Detection. Fort Belvoir, VA: Defense Technical Information Center, Januar 2014. http://dx.doi.org/10.21236/ada599174.

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Bily, Mollie A., Young W. Kwon und Randall D. Pollak. Damage Detection in Composite Interfaces through Carbon Nanotube Reinforcement. Fort Belvoir, VA: Defense Technical Information Center, Februar 2010. http://dx.doi.org/10.21236/ada516359.

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Clark, G., C. Robbins, K. Wade und P. Souza. Cable Damage Detection System and Algorithms Using Time Domain Reflectometry. Office of Scientific and Technical Information (OSTI), März 2009. http://dx.doi.org/10.2172/971773.

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Alfred E. Crouch, Alan Dean, Carl Torres und Jeff Aron. DEVELOPMENT OF NONLINEAR HARMONIC SENSORS FOR DETECTION OF MECHANICAL DAMAGE. Office of Scientific and Technical Information (OSTI), März 2004. http://dx.doi.org/10.2172/825669.

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Islam, Abu S., und Kevin Craig. Damage Detection and Mitigation of Composite Structures using Smart Materials. Fort Belvoir, VA: Defense Technical Information Center, Januar 1993. http://dx.doi.org/10.21236/ada261121.

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