The Experts below are selected from a list of 51381 Experts worldwide ranked by ideXlab platform
Peng Liu - One of the best experts on this subject based on the ideXlab platform.
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Damage Mode identification and singular signal detection of composite wind turbine blade using acoustic emission
Composite Structures, 2021Co-Authors: Peng Liu, Zhicai ChenAbstract:Abstract Some challenging issues emerge for the health monitoring of composite wind turbine blades under the intrinsic noise of fatigue loading, including Damage Mode identification and singular signal detection. This work performs health monitoring of a 59.5-m-long composite wind turbine blade under fatigue loads by acoustic emission (AE) technique. First, the original AE waveform is acquired after wave attenuation calibration and sensor array arrangement. Second, a waveform-based feature extraction method is developed based on the wavelet packet decomposition (WPD) to capture the information contained in original AE signals, which covers all features for reconstructed signals in the frequency domain. Without the requirements for signal preprocessing, clustering analysis is conducted for Damage Mode identification and singular signal detection based on the extracted features. Third, two hyperparameters, including the scatter number and the selection of wavelet basis function, are demonstrated to show no effect on the results, indicating the robustness of the method. This method is proved to be effective and feasible for health condition monitoring of the blade.
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A waveform clustering method for Damage Mode identification for composite laminates under hygrothermal environment
Engineering Fracture Mechanics, 2020Co-Authors: Peng Liu, Zhicai ChenAbstract:Abstract This work performs acoustic emission monitoring of Damage behaviors in carbon fiber/ epoxy composite laminates during tensile loads under hygrothermal environment. First, a waveform-based clustering method is introduced by employing the wavelet packet decomposition (WPD), the Shannon’s entropy, the cosine similarity and the clustering algorithm. Second, based on the clustering results, the characteristic features of various Damage Modes are derived. Finally, further investigation is carried out to explore the effects of hygrothermal aging on the Damage source localization, Damage initiation and evolution. From the theoretical analysis, several conclusions are obtained: 1. Fiber breakage behaves as a combination of matrix cracking, fiber/matrix interface debonding and delamination in the space of extracted features. 2. The frequency response of each Damage Mode is demonstrated to be degraded after hygrothermal aging. The principal features of fiber/matrix interface debonding and delamination are found to be significantly affected by hygrothermal aging as compared to other two Damage Modes. 3. The distortion of the principal feature of each micro-Damage Mode is found to be negligible with the Damage accumulation, indicating the robustness of the method.
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Achieving robust Damage Mode identification of adhesive composite joints for wind turbine blade using acoustic emission and machine learning
Composite Structures, 2020Co-Authors: Peng Liu, Zhong-liang Chen, Jianxing Leng, L. JiaoAbstract:Abstract Interest in Damage Mode classification of composite structures by Acoustic Emission (AE) inspection technique and clustering analysis by machine learning has been increasingly growing. Furthermore, hyperparameters in clustering analysis promote the need for more robust clustering algorithms. This paper presents a clustering method by fast search and find of density peaks (CFSFDP), where robust identification for different Damage Modes can be achieved by means of similarities of AE signals. Based on the clustering analysis, matrix cracking and shear failure of the adhesive layer are demonstrated to be fundamental and characteristic Damage Modes, respectively. Meanwhile, similarities of AE signals for various Damage Modes in the subspace of AE features are explored in detail. The interface debonding (fiber/matrix interface debonding and adhesive failure) and the cracking of polymer (matrix cracking and cohesive failure) behave similarly in the subspace of selected AE features. As a different Damage Mode, fiber breakage is shown to be more similar to delamination, in contrast with other Damage Modes in the subspace. Moreover, effects of the selection of cluster number, the metric of spatial similarity and the value of cutoff index on the clustering results are shown to be negligible.
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Damage Mode identification of adhesive composite joints under hygrothermal environment using acoustic emission and machine learning
Composite Structures, 2019Co-Authors: Peng Liu, Zhong-liang ChenAbstract:Abstract This paper studies the hygrothermal aging effect on the Damage behaviors of adhesive composite joints by acoustic emission (AE) technique. Tensile tests and AE tests are launched for both non-aging and aging specimens under regular and hygrothermal environments, respectively. The clustering analysis, the time-domain analysis and the frequency-domain analysis are combined to identify various Damage Modes and to study the hygrothermal aging effect of single-lap joint (SLJ). First, the clustering analysis is performed to study the Damage Mode correlation using four AE characteristic parameters including the time of duration, the peak amplitude, the RA value (the rise time divided by the peak amplitude) and the frequency centroid of gravity. Then, the time-domain analysis is conducted to investigate the hygrothermal effect of the single-lap joint (SLJ). Finally, the frequency spectrum analysis is carried out to study the frequency range for the shear failure of adhesive layer. In addition, the dominant Damage Mode of SLJ is identified using the wavelet-based decomposition of the ultimate AE signals with the largest energy.
Gilbert Fantozzi - One of the best experts on this subject based on the ideXlab platform.
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unsupervised and supervised classification of ae data collected during fatigue test on cmc at high temperature
Composites Part A-applied Science and Manufacturing, 2012Co-Authors: S Momon, Nathalie Godin, Pascal Reynaud, Mohamed Rmili, Gilbert FantozziAbstract:Abstract This paper aims at giving a better understanding of Damage mechanisms that control lifetime of C f /SiC composites at high temperatures (700–1200 °C) under static and cyclic fatigue. Acoustic emission (AE) signals were analysed with a view to identify classes corresponding to a specific Damage Mode. An unsupervised classification method allowed differentiating signals resulting from the following Damage mechanisms: collective or individual fibre breaks, matrix cracking, fibre/matrix debonding, yarn/yarn debonding and sliding at fibre/matrix interfaces or matrix cracks closing after unloading. Then, a supervised classification method was developed. It allows real-time identification of Damage mechanisms regardless of testing conditions (temperature, applied load and loading Mode).
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Unsupervised and supervised classification of AE data collected during fatigue test on CMC at high temperature
Composites Part A: Applied Science and Manufacturing, 2012Co-Authors: S Momon, Nathalie Godin, Pascal Reynaud, Mohamed R'mili, Gilbert FantozziAbstract:This paper aims at giving a better understanding of Damage mechanisms that control lifetime of C f/SiC composites at high temperatures (700-1200°C) under static and cyclic fatigue. Acoustic emission (AE) signals were analysed with a view to identify classes corresponding to a specific Damage Mode. An unsupervised classification method allowed differentiating signals resulting from the following Damage mechanisms: collective or individual fibre breaks, matrix cracking, fibre/matrix debonding, yarn/yarn debonding and sliding at fibre/matrix interfaces or matrix cracks closing after unloading. Then, a supervised classification method was developed. It allows real-time identification of Damage mechanisms regardless of testing conditions (temperature, applied load and loading Mode). © 2011 Elsevier Ltd. All rights reserved.
Bijan Mohammadi - One of the best experts on this subject based on the ideXlab platform.
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Representative volume element-based simulation of multiple solid particles erosion of a compressor blade considering temperature effect:
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2019Co-Authors: Bijan Mohammadi, Amirsajjad KhoddamiAbstract:Solid particle erosion is one of the main failure mechanisms of a compressor blade. Thus, characterization of this Damage Mode is very important in life assessment of the compressor. Since experime...
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Prediction of outer-ply matrix crack density at saturation in laminates under static and fatigue loading
International Journal of Solids and Structures, 2018Co-Authors: Hamed Pakdel, Bijan MohammadiAbstract:Abstract The onset of dominant Damage Mode transition from matrix cracking to induced delamination in laminates containing outer-ply matrix cracks is experimentally and analytically investigated. Stress states of a [ θ m ( o ) / θ n ( i ) ] s laminate containing staggered outer-ply matrix cracks with or without induced delaminations are derived implementing a developed unit-cell based analysis in the framework of variational principles. A Damage Mode competition criterion is implemented to predict crack density at saturation which is argued to be a characteristic Damage state (CDS) independent from loading conditions. Several carbon/epoxy specimens of type [θm/0n]s are prepared with different off-axis ply orientation, θ, and thickness. Optical microscopy is used to identify matrix crack density during both static and fatigue loading with different loading conditions. The analytically predicted crack densities at saturation are shown to be in acceptable agreement with experimental observations and saturated crack density is confirmed to be a characteristic Damage state (CDS) identical during both static and fatigue loading.
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experimental and numerical study of oblique transverse cracking in cross ply laminates under tension
Composites Part A-applied Science and Manufacturing, 2014Co-Authors: Meisam Jalalvand, H Hosseinitoudeshky, Michael R Wisnom, Bijan MohammadiAbstract:The first Damage Mode in cross-ply laminates under tension is broadly accepted as transverse cracks normal to the loading direction in the 90° layers, but there is not the same agreement about the second Damage Mode. While most of the analytical and experimental results are based on delamination induced by transverse cracking, another type of Damage, oblique cracks within the 90° layers, has also been observed as the second Damage Mode in [0/904]s laminates. To understand the cause of this phenomenon, FE analyses considering Damage development at the interfaces were performed. The obtained results indicate that the main reason for the oblique cracking Damage Mode is the higher toughness of the material in Mode-II compared with Mode-I: when the value of shear toughness is close to the opening toughness, the second Damage Mode in cross-ply laminates under tensile loading is delamination induced by transverse cracks, however, if the difference between the two values is large, oblique cracks in the 90° layers are likely to appear. In the specific tested and analysed laminate, if the Mode II toughness is double the Mode I toughness, oblique cracking occurs but if the values of Mode I and Mode II toughness are close, delamination is the second Damage Mode.
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Experimental and numerical study of oblique transverse cracking in cross-ply laminates under tension Part A Applied science and manufacturing
Composites, 2014Co-Authors: Meisam Jalalvand, Michael R Wisnom, Hossein Hosseini-toudeshky, Bijan MohammadiAbstract:The first Damage Mode in cross-ply laminates under tension is broadly accepted as transverse cracks normal to the loading direction in the 90° layers, but there is not the same agreement about the second Damage Mode. While most of the analytical and experimental results are based on delamination induced by transverse cracking, another type of Damage, oblique cracks within the 90° layers, has also been observed as the second Damage Mode in [0/904]s laminates. To understand the cause of this phenomenon, FE analyses considering Damage development at the interfaces were performed. The obtained results indicate that the main reason for the oblique cracking Damage Mode is the higher toughness of the material in Mode-II compared with Mode-I: when the value of shear toughness is close to the opening toughness, the second Damage Mode in cross-ply laminates under tensile loading is delamination induced by transverse cracks, however, if the difference between the two values is large, oblique cracks in the 90° layers are likely to appear. In the specific tested and analysed laminate, if the Mode II toughness is double the Mode I toughness, oblique cracking occurs but if the values of Mode I and Mode II toughness are close, delamination is the second Damage Mode.
Mostapha Tarfaoui - One of the best experts on this subject based on the ideXlab platform.
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Damage detection versus heat dissipation in e glass epoxy laminated composites under dynamic compression at high strain rate
Composite Structures, 2018Co-Authors: Mostapha Tarfaoui, El A Moume, E H YahiaAbstract:Abstract In this investigation, a new experimental technique in which the deformation, Damage Mode, and the temperature are measured simultaneously during a high strain rate on laminated composites materials. The composites consist of unidirectional E-glass fibers reinforced epoxy polymer composites used in industrial applications. The experimental setup consists of a compression Split Hopkinson Pressure Bar (SHPB), a high-speed infrared camera and a high-speed Fastcam rapid camera. Specimens, with cubic like a shape, are impacted at different strain rates ranging from 200 to 2000 s−1. During impact test, the specimen surface is controlled and monitored with the infrared camera which provides thermal images in time sequence and with high-speed camera which acquires the Damage progressive in specimens. Experimental results show that the Damage throughout specimens differs and the temperature change depending on the Damage Mode and their maximum exceed 219 °C.
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Damage detection versus heat dissipation in E-glass/Epoxy laminated composites under dynamic compression at high strain rate
Composite Structures, 2018Co-Authors: Mostapha Tarfaoui, Ahmed El Moumen, Hamza Ben YahiaAbstract:In this investigation, a new experimental technique in which the deformation, Damage Mode, and the temperature are measured simultaneously during a high strain rate on laminated composites materials. The composites consist of unidirectional E-glass fibers reinforced epoxy polymer composites used in industrial applications. The experimental setup consists of a compression Split Hopkinson Pressure Bar (SHPB), a high-speed infrared camera and a high-speed Fastcam rapid camera. Specimens, with cubic like a shape, are impacted at different strain rates ranging from 200 to 2000 s(-1). During impact test, the specimen surface is controlled and monitored with the infrared camera which provides thermal images in time sequence and with high-speed camera which acquires the Damage progressive in specimens. Experimental results show that the Damage throughout specimens differs and the temperature change depending on the Damage Mode and their maximum exceed 219 degrees C.
Claire L. Brockett - One of the best experts on this subject based on the ideXlab platform.
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Damage Mode ANALYSIS OF 22 AES TOTAL ANKLE REPLACEMENT EXPLANTS
2018Co-Authors: A. Stratton-powell, Joanne L. Tipper, Sophie Williams, Anthony C. Redmond, Claire L. BrockettAbstract:Total ankle replacement (TAR) has a mean survivorship of 77% at 10 years which is poor compared to other types of joint arthroplasty. Osteolysis and aseptic loosening are commonly cited TAR failure Modes, the mechanisms of which are unknown. Retrieval analyses of TAR devices may reveal mechanisms of failure similar or dissimilar to other joint replacements. This study investigated whether TAR explants exhibit similar Damage Modes to those recognised in other total joint replacements.22 Ankle Evolution System TARs (Transysteme, Nimes, France) were implanted and retrieved by the same surgeon. Mean implantation time was 7.8 yrs (5.3 to 12.1 range). Pain and/or loosening were the indications for revision. Macro photography, an Alicona Infinite microscope and the Hood/Wasielewski scale were used to classify Damage Modes on the polyethylene insert. Scanning electron microscopy with energy dispersive X-ray spectroscopy was used to determine the composition of third body debris and to image the fixation surface o...
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Damage Mode ANALYSIS OF 22 AES TOTAL ANKLE REPLACEMENT EXPLANTS
Journal of Bone and Joint Surgery-british Volume, 2016Co-Authors: A. Stratton-powell, Joanne L. Tipper, Sophie Williams, Anthony C. Redmond, Claire L. BrockettAbstract:Total ankle replacement (TAR) has a mean survivorship of 77% at 10 years which is poor compared to other types of joint arthroplasty. Osteolysis and aseptic loosening are commonly cited TAR failure Modes, the mechanisms of which are unknown. Retrieval analyses of TAR devices may reveal mechanisms of failure similar or dissimilar to other joint replacements. This study investigated whether TAR explants exhibit similar Damage Modes to those recognised in other total joint replacements. 22 Ankle Evolution System TARs (Transysteme, Nimes, France) were implanted and retrieved by the same surgeon. Mean implantation time was 7.8 yrs (5.3 to 12.1 range). Pain and/or loosening were the indications for revision. Macro photography, an Alicona Infinite microscope and the Hood/Wasielewski scale were used to classify Damage Modes on the polyethylene insert. Scanning electron microscopy with energy dispersive X-ray spectroscopy was used to determine the composition of third body debris and to image the fixation surface of the tibial components. Mean Damage score was 185.4 (± 40.0 SD). Damage Modes common to total knee replacements were identified on both the superior and inferior insert surfaces, these included: burnishing, scratching, pitting and abrasion. Titanium particles, hydroxyapatite fragments and bone debris were embedded in the insert surfaces. Fixation surface delamination was identified by the ongrowth of tissue between the cobalt chromium substrate and titanium alloy coating. Damage Modes indicative of high levels of wear and deformation were evident. Pitting caused by third body debris was abundant and suggested fixation surface wear and failure.
