Searched for: subject%3A%22Lamb%255C+waves%22
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Li, Tianzhi (author), Chen, Jian (author), Yuan, Shenfang (author), Zarouchas, D. (author), Sbarufatti, Claudio (author), Cadini, Francesco (author)
Fatigue damage prognosis always requires a degradation model describing the damage evolution with time; thus, the prognostic performance highly depends on the selection of such a model. The best model should probably be case specific, calling for the fusion of multiple degradation models for a robust prognosis. In this context, this paper...
journal article 2024
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Ewald, Vincentius (author)
One of the classical solutions to maintain the aircraft structural integrity is to rely on the analysis of non-destructive testing (NDT) inspector with various inspection methods. However, it is relatively expensive in matter of time and costs to train human resources until the certification is reached. Further, in majority of the cases of...
doctoral thesis 2023
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Yue, N. (author), Galanopoulos, Georgios (author), Loutas, Theodoros (author), Zarouchas, D. (author)
During the service of composite airframes, damage initiates and accumulates due to the manufacturing imperfections, impact damage and cyclic loadings, leading to the degradation in its load-bearing capacity. The nature of the degradation process is complicated due to the multi-mode damage propagation and complexity in the structural details...
conference paper 2023
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Nokhbatolfoghahai, A. (author), M. Navazi, H. (author), Groves, R.M. (author)
In this paper, to increase the performance of the sparse reconstruction method in real complex engineering structures an adaptive dictionary learning framework is proposed which updates the dictionary matrix, to allow improved compatibility with the complex structure. This proposed framework was developed by combining analytical modeling with...
journal article 2022
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Sabbadini, A. (author), Massaad Mouawad, J.M. (author), van Neer, P.L.M.J. (author), de Jong, N. (author), Verweij, M.D. (author)
In recent years, several fitting techniques have been presented to reconstruct the parameters of a plate from its Lamb wave dispersion curves. Published studies show that these techniques can yield high accuracy results and have the potential of reconstructing several parameters at once. The precision with which parameters can be...
journal article 2022
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Sabbadini, A. (author)
Diastolic heart failure is one of the principal causes of death in Western countries, and there is currently no treatment available; prevention, on the other hand, may be possible, provided an early enough diagnosis. The worsening of diastolic functionality is associated with increased values of cardiac stiffness, which could therefore provide a...
doctoral thesis 2021
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Massaad Mouawad, J.M. (author)
Ultrasonic flow meters are widely applied to measure flow in a variety of applications. The vast majority of ultrasonic flow meters are based on the measurement of the transit time of an acoustic pulse through the fluid. This can either be done in-line, by inserting a spool piece with ultrasonic transducers into the pipe carrying the fluid, or...
doctoral thesis 2021
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Massaad Mouawad, J.M. (author), van Neer, P.L.M.J. (author), van Willigen, D.M. (author), Sabbadini, A. (author), de Jong, N. (author), Pertijs, M.A.P. (author), Verweij, M.D. (author)
Current ultrasonic clamp-on flow meters consist of a pair of single-element transducers that are carefully positioned before use. This positioning process consists of manually finding the distance between the transducer elements, along the pipe axis, for which maximum signal-to-noise ratio (SNR) is achieved. This distance depends on the sound...
journal article 2021
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Nokhbatolfoghahai, A. (author), Navazi, H. M. (author), Groves, R.M. (author)
In this paper, the performance of the sparse reconstruction (SR) and the delay-and-sun (DAS) methods for damage localization, were evaluated for various environmental and operational conditions, both numerically and experimentally. To assess these damage localization methods, a methodology based on the Taguchi method was used to make the...
journal article 2021
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Cheng, L. (author), Xin, H. (author), Groves, R.M. (author), Veljkovic, M. (author)
Acoustic emission (AE) is often used for structural health monitoring (SHM) in the wide field of engineering structures and one of its most beneficial attributes is the ability to localize the damage/crack based on the AE events. The vast majority of ongoing work on AE monitoring focues on geometrically simple structures or a confined area,...
journal article 2021
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Ewald, Vincentius (author), Sridaran Venkat, Ramanan (author), Asokkumar, Aadhik (author), Benedictus, R. (author), Boller, Christian (author), Groves, R.M. (author)
Predictive maintenance, as one of the core components of Industry 4.0, takes a proactive approach to maintain machines and systems in good order to keep downtime to a minimum and the airline maintenance industry is not an exception to this. To achieve this goal, practices in Structural Health Monitoring (SHM) complement the existing Non...
journal article 2021
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Falcetelli, F. (author), Venturini, Nicolas (author), Barroso Romero, M. (author), Martinez, Marcias J. (author), Pant, Shashank (author), Troiani, Enrico (author)
Structural Health Monitoring (SHM) aims to shift aircraft maintenance from a time-based to a condition-based approach. Within all the SHM techniques, Acoustic Emission (AE) allows for the monitoring of large areas by analyzing Lamb waves propagating in plate like structures. In this study, the authors proposed a Time Reversal (TR) methodology...
journal article 2021
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Mozaffarzadeh, M. (author), Minonzio, C.G. (author), de Jong, N. (author), Verweij, M.D. (author), Hemm, Simone (author), Daeichin, V. (author)
Phase aberration in transcranial ultrasound imaging (TUI) caused by the human skull leads to an inaccurate image reconstruction. In this article, we present a novel method for estimating the speed of sound and an adaptive beamforming technique for phase aberration correction in a flat polyvinylchloride (PVC) slab as a model for the human...
journal article 2020
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Nokhbatolfoghahai, A. (author), Navazi, H. M. (author), Groves, R.M. (author)
In this paper, the hybrid Delay-And-Sum (DAS) with Sparse Reconstruction (SR) method was further developed for damage location in composite plates. In composite materials, anisotropy leads to some challenges in using conventional damage location methods, which are developed for isotropic materials. In the hybrid DAS-SR method, the DAS and SR...
journal article 2020
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Saeedifar, M. (author), Mansvelder, Jasmijn (author), Mohammadi, R. (author), Zarouchas, D. (author)
This study aims to use the passive and active acoustic-based health monitoring methods for impact damage assessment of composite structures. To this aim, a Carbon Fiber Reinforced Polymer (CFRP) composite plate was fabricated and subjected to a simulated low-velocity impact by performing repeated quasi-static indentation tests where a loading...
journal article 2019
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Zarouchas, D. (author), Saeedifar, M. (author)
This study aims to demonstrate the effectiveness of blending passive and active acoustic-based health monitoring methods to impact damage diagnostics of composite structures. The structural state awareness is introduced as a term to characterize the health condition that a structure is and how this condition can be quantified by blending...
conference paper 2019
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Nokhbatolfoghahai, A. (author), Navazi, Hossein M. (author), Groves, R.M. (author)
To perform active structural health monitoring, guided Lamb waves for damage detection have recently gained extensive attention. Many algorithms are used for damage detection with guided waves and among them, the delay-and-sum method is the most commonly used algorithm because of its robustness and simplicity. However, delay-and-sum images...
journal article 2019
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Ewald, Vincentius (author), Groves, R.M. (author), Benedictus, R. (author)
In our previous work, we demonstrated how to use inductive bias to infuse a convolutional neural network (CNN) with domain knowledge from fatigue analysis for aircraft visual NDE. We extend this concept to SHM and therefore in this paper, we present a novel framework called DeepSHM which involves data augmentation of captured sensor signals...
conference paper 2019
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Ewald, Vincentius (author), Groves, R.M. (author), Benedictus, R. (author)
In this paper, we investigated transducer placement strategies for detecting cracks in primary aircraft structures using ultrasonic Structural Health Monitoring (SHM). The approach developed is for an expected damage location based on fracture mechanics, for example fatigue crack growth in a high stress location. To assess the performance of the...
journal article 2018
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Ochôa, Pedro (author), Villegas, I.F. (author), Groves, R.M. (author), Benedictus, R. (author)
One of the advantages of thermoplastic composites relative to their thermoset counterparts is the possibility of assembling components through welding. Ultrasonic welding in particular is very promising for industrialization. However, uncertainty in the fatigue and fracture behaviour of composites is still an obstacle to the full utilisation...
journal article 2018
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