A novel data processing algorithm for the generation of tomographic images of composite materials, based on measurements acquired via frequency-modulated continuous-wave (FMCW) radars operating in the millimeter wave regime, is presented. The presented algorithm, in tandem with the applied method and achieved results, provides valuable information for the optimization of the quality and efficiency of composite-based components. By utilizing the high sensitivity of the signals' phase, the detection and classification of defect type, shape, and position are possible. Since the ambiguity of the phase generates radar images resembling optical fringe patterns, the data evaluation is inspired by the respective fringe pattern analysis, as often utilized in optics. The signal processing is adapted accordingly to match the radar-based data. To demonstrate the feasibility of the proposed algorithm, glass fiber reinforced plastic samples with deliberate and predefined defects, including resin wedges and dry fibers, are measured with a radar system operating in W-band (75-110 GHz), with the used bandwidth of 24 GHz and the signal focused to the sample under test.
16 septembre 2019
Millimeter-Wave Tomographic Imaging of Composite Materials Based on Phase Evaluation - IEEE Journals & Magazine
Millimeter-Wave Tomographic Imaging of Composite Materials Based on Phase Evaluation - IEEE Journals & Magazine
A novel data processing algorithm for the generation of tomographic images of composite materials, based on measurements acquired via frequency-modulated continuous-wave (FMCW) radars operating in the millimeter wave regime, is presented. The presented algorithm, in tandem with the applied method and achieved results, provides valuable information for the optimization of the quality and efficiency of composite-based components. By utilizing the high sensitivity of the signals' phase, the detection and classification of defect type, shape, and position are possible. Since the ambiguity of the phase generates radar images resembling optical fringe patterns, the data evaluation is inspired by the respective fringe pattern analysis, as often utilized in optics. The signal processing is adapted accordingly to match the radar-based data. To demonstrate the feasibility of the proposed algorithm, glass fiber reinforced plastic samples with deliberate and predefined defects, including resin wedges and dry fibers, are measured with a radar system operating in W-band (75-110 GHz), with the used bandwidth of 24 GHz and the signal focused to the sample under test.
A novel data processing algorithm for the generation of tomographic images of composite materials, based on measurements acquired via frequency-modulated continuous-wave (FMCW) radars operating in the millimeter wave regime, is presented. The presented algorithm, in tandem with the applied method and achieved results, provides valuable information for the optimization of the quality and efficiency of composite-based components. By utilizing the high sensitivity of the signals' phase, the detection and classification of defect type, shape, and position are possible. Since the ambiguity of the phase generates radar images resembling optical fringe patterns, the data evaluation is inspired by the respective fringe pattern analysis, as often utilized in optics. The signal processing is adapted accordingly to match the radar-based data. To demonstrate the feasibility of the proposed algorithm, glass fiber reinforced plastic samples with deliberate and predefined defects, including resin wedges and dry fibers, are measured with a radar system operating in W-band (75-110 GHz), with the used bandwidth of 24 GHz and the signal focused to the sample under test.
A comprehensive review on contemporary materials used for blades of wind turbine - ScienceDirect
A comprehensive review on contemporary materials used for blades of wind turbine - ScienceDirect
Many researchers have exploited the merits of advanced materials in fabrication of wind turbine blades. The required material properties like good fatigue strength to resist the cyclic load, less weight to decease gravitational forces, great strength to resist gravitational and wind forces, larger stiffness to provide stability are investigated and reviewed in this article. It is recognized that, the acceptable mechanical properties are obtained by reinforcing the composites with nano materials. The carbon nanotube fibers (CNT|s), an allotrope of carbon possess nanostructure of excellent aspect ratio which is higher than 1,000,000. Due to the distinctive properties of cylindrical carbon molecules, it is much preferred in wind turbine blades. CNTs are fabricated with various reinforcements for obtaining enhanced properties, which is reviewed in this work, and contrasted with traditional materials which are utilized in wind turbine blades. Hence, the main aim of this review is to suggest an appropriate material for wind turbine blade applications.
Many researchers have exploited the merits of advanced materials in fabrication of wind turbine blades. The required material properties like good fatigue strength to resist the cyclic load, less weight to decease gravitational forces, great strength to resist gravitational and wind forces, larger stiffness to provide stability are investigated and reviewed in this article. It is recognized that, the acceptable mechanical properties are obtained by reinforcing the composites with nano materials. The carbon nanotube fibers (CNT|s), an allotrope of carbon possess nanostructure of excellent aspect ratio which is higher than 1,000,000. Due to the distinctive properties of cylindrical carbon molecules, it is much preferred in wind turbine blades. CNTs are fabricated with various reinforcements for obtaining enhanced properties, which is reviewed in this work, and contrasted with traditional materials which are utilized in wind turbine blades. Hence, the main aim of this review is to suggest an appropriate material for wind turbine blade applications.
Linear and nonlinear buckling analysis for the material design optimization of wind turbine blades | Emerald Insight
Linear and nonlinear buckling analysis for the material design optimization of wind turbine blades | Emerald Insight
The purpose of this paper is to investigate the buckling behavior of the load-carrying support structure of a wind turbine blade.
The purpose of this paper is to investigate the buckling behavior of the load-carrying support structure of a wind turbine blade.
Alternatives on afterlife use of amortized wind turbine blades in the Netherlands - University of Twente Student Theses
Alternatives on afterlife use of amortized wind turbine blades in the Netherlands - University of Twente Student Theses
Wind energy has been growing and evolving in the past decades. The size of the wind turbine blades have also been increasing and with a life expectancy of around 15-25 years depending on the wind class of the blades, there are little afterlife applications currently available for these blades. Recyclability of the blades is complicated due to the fact that it is made from composite materials, mostly epoxy and fiber glass. This creates an obstacle for the amortized blades, since disposing solid wastes in landfills have been restricted through legislation within the European Union (EU). With the current situation and the aim of many EU nations to reach their Sustainable Development Goals in 2030 and 2050, there is no doubt that these countries will have to find options to deal with the amortized blades. As the title states alternative methods on processing the end of life (EoL) wind turbine (W.T.) blades most likely applicable in the Netherlands and the EU or the globe will be discussed. Four methods are discussed namely: pyrolysis, refurbishing, pavement application and landfilling of the amortized/EoL W.T. blades The most prominent options of dealing with the end-of-life rotor blades are: burning of the blades cut in pieces and use the heat to generate energy, pyrolysis and use the filler material in cement. Another option is to use the blade as an artificial reef which can be if given some time, beneficial in ecological terms. The artificial reef would function as a breeding place for a number of undersea life species. All the aforementioned options are viable solutions, but still face many obstacles due to lack of equipment and policies regulating and stimulating recycling the blades, transportation costs and maturity of applicable technology available at the moment.
Wind energy has been growing and evolving in the past decades. The size of the wind turbine blades have also been increasing and with a life expectancy of around 15-25 years depending on the wind class of the blades, there are little afterlife applications currently available for these blades. Recyclability of the blades is complicated due to the fact that it is made from composite materials, mostly epoxy and fiber glass. This creates an obstacle for the amortized blades, since disposing solid wastes in landfills have been restricted through legislation within the European Union (EU). With the current situation and the aim of many EU nations to reach their Sustainable Development Goals in 2030 and 2050, there is no doubt that these countries will have to find options to deal with the amortized blades. As the title states alternative methods on processing the end of life (EoL) wind turbine (W.T.) blades most likely applicable in the Netherlands and the EU or the globe will be discussed. Four methods are discussed namely: pyrolysis, refurbishing, pavement application and landfilling of the amortized/EoL W.T. blades The most prominent options of dealing with the end-of-life rotor blades are: burning of the blades cut in pieces and use the heat to generate energy, pyrolysis and use the filler material in cement. Another option is to use the blade as an artificial reef which can be if given some time, beneficial in ecological terms. The artificial reef would function as a breeding place for a number of undersea life species. All the aforementioned options are viable solutions, but still face many obstacles due to lack of equipment and policies regulating and stimulating recycling the blades, transportation costs and maturity of applicable technology available at the moment.
Fatigue Life of Megawatt-Scale Composite Wind Turbine Blades with Shallow-Angled Laminates | SpringerLink
Fatigue Life of Megawatt-Scale Composite Wind Turbine Blades with Shallow-Angled Laminates | SpringerLink
The fatigue life of megawatt-scale composite wind turbine blades implemented with shallow-angled laminates is investigated. Full dynamic simulations of a 5-MW 3-bladed horizontal-axis wind turbine were carried out to estimate the incident fatigue loads. The fatigue stress histories experienced by lay up materials were then computed using a finite-element model of the composite blade developed to ply-level details. Thereafter, the fatigue life of blade was estimated considering the 100% availability of the turbine for the site-specific annual wind distribution related to the wind turbine class IB. It is demonstrated that the application of shallow-angled laminates leads to a more durable design.
The fatigue life of megawatt-scale composite wind turbine blades implemented with shallow-angled laminates is investigated. Full dynamic simulations of a 5-MW 3-bladed horizontal-axis wind turbine were carried out to estimate the incident fatigue loads. The fatigue stress histories experienced by lay up materials were then computed using a finite-element model of the composite blade developed to ply-level details. Thereafter, the fatigue life of blade was estimated considering the 100% availability of the turbine for the site-specific annual wind distribution related to the wind turbine class IB. It is demonstrated that the application of shallow-angled laminates leads to a more durable design.
Fiber-Reinforced Cement Composites: Mechanical Properties and Structural Implications 2019
Fiber-Reinforced Cement Composites: Mechanical Properties and Structural Implications 2019
n order to overcome inherent brittleness of concrete, numerous studies on the development of high ductility fiber-reinforced cement composites have been performed thus far. Several different types of fiber-reinforced cement composites with metallic, polymer, carbon, glass, nylon, and waste tire fibers have been successfully developed and effectively applied for building structures due to their benefits of limiting crack propagation and widening from fiber bridging. High-performance fiber-reinforced cement composites showing strain- or deflection-hardening behavior with multiple microcracks were recently developed, and various relevant studies are actively underway.This special issue gives a comprehensive overview on fiber-reinforced cement composites, including aspects related to material behavior, strengthening performance, numerical simulation and modeling, and structural implication under various loading conditions (i.e., static, impact, blast, fire, fatigue, etc.). The selection of papers in this special issue was very rigorous...
n order to overcome inherent brittleness of concrete, numerous studies on the development of high ductility fiber-reinforced cement composites have been performed thus far. Several different types of fiber-reinforced cement composites with metallic, polymer, carbon, glass, nylon, and waste tire fibers have been successfully developed and effectively applied for building structures due to their benefits of limiting crack propagation and widening from fiber bridging. High-performance fiber-reinforced cement composites showing strain- or deflection-hardening behavior with multiple microcracks were recently developed, and various relevant studies are actively underway.This special issue gives a comprehensive overview on fiber-reinforced cement composites, including aspects related to material behavior, strengthening performance, numerical simulation and modeling, and structural implication under various loading conditions (i.e., static, impact, blast, fire, fatigue, etc.). The selection of papers in this special issue was very rigorous...
Aerogami: Composite Origami Structures as Active Aerodynamic Control
Aerogami: Composite Origami Structures as Active Aerodynamic Control: This study explores the use of origami composite structures as active aerodynamic control surfaces. Towards this goal, two origami concepts were designed leveraging a combination of analytical and finite element modeling, and computational fluid dynamics simulations. Wind tunnel tests were performed at different dynamic pressures in conjunction with two different active control laws to test the capability of obtaining desired drag values. The experiments revealed excellent structural rigidity and folding characteristics under aerodynamic loading. Future work will focus on developing advanced origami designs that allow for more deterministic folding as well as improved weight, stiffness, and fatigue characteristics in the use of materials. Upon completion of these improvements, it is anticipated that full-scale testing on a vehicle could be meaningfully conducted.
2 septembre 2019
Tunneling Crack Initiation in Trailing-Edge Bond Lines of Wind-Turbine Blades | AIAA Journal
Tunneling Crack Initiation in Trailing-Edge Bond Lines of Wind-Turbine Blades | AIAA Journal
Tunneling cracks are observed in the adhesive of the trailing-edge bond line of wind-turbine rotor blades subjected to high-cycle fatigue. To identify the root causes of these cracks, their initiation was calculated using a stress-based approach. The mechanical stresses caused by aerodynamic and gravity loads, which arise when operating in the field, were considered on the one hand, and the residual stresses caused by thermal material shrinkage during manufacture on the other. This work investigates the impact of each mechanical stress and thermal residual stress component on the fatigue stress exposure along the blade span. It was found that the thermal residual stresses make a significant contribution to the bond-line fatigue. Besides the dominating longitudinal stress, peel and shear stress also contribute to the fatigue...
Tunneling cracks are observed in the adhesive of the trailing-edge bond line of wind-turbine rotor blades subjected to high-cycle fatigue. To identify the root causes of these cracks, their initiation was calculated using a stress-based approach. The mechanical stresses caused by aerodynamic and gravity loads, which arise when operating in the field, were considered on the one hand, and the residual stresses caused by thermal material shrinkage during manufacture on the other. This work investigates the impact of each mechanical stress and thermal residual stress component on the fatigue stress exposure along the blade span. It was found that the thermal residual stresses make a significant contribution to the bond-line fatigue. Besides the dominating longitudinal stress, peel and shear stress also contribute to the fatigue...
A Review on Suspension Thermal Spray Patented Technology Evolution | SpringerLink
A Review on Suspension Thermal Spray Patented Technology Evolution | SpringerLink
Since the introduction of suspension thermal spray (STS) in 1997, the rapid evolution of this technology has resulted in a critical number of inventions justifying a comprehensive review. Today STS is one of the most important research and development topics in thermal spray. Due to the efforts of different industries, universities, and governmental institutions, STS has reached a certain maturity for implementation in different applications. STS includes any thermal spray process that is based on injection of a suspension of solid particles in a liquid carrier into the gas jet, such as suspension plasma spray, suspension high-velocity oxy-fuel, and high-velocity suspension flame spray......
Since the introduction of suspension thermal spray (STS) in 1997, the rapid evolution of this technology has resulted in a critical number of inventions justifying a comprehensive review. Today STS is one of the most important research and development topics in thermal spray. Due to the efforts of different industries, universities, and governmental institutions, STS has reached a certain maturity for implementation in different applications. STS includes any thermal spray process that is based on injection of a suspension of solid particles in a liquid carrier into the gas jet, such as suspension plasma spray, suspension high-velocity oxy-fuel, and high-velocity suspension flame spray......
Confusion about infusion: An overview of infusion processes - ScienceDirect
Confusion about infusion: An overview of infusion processes - ScienceDirect
Today the impregnation of dry fibre materials is a production method preferred for large composite parts like wind turbine rotor blades or aircraft wing covers. This trend has led many researchers and many companies to deal with new processes or process modifications. Therefore, vacuum infusion is a term with many acronyms. It cannot always be clearly assigned whether a method is a new process or a modification of existing processes.....
Today the impregnation of dry fibre materials is a production method preferred for large composite parts like wind turbine rotor blades or aircraft wing covers. This trend has led many researchers and many companies to deal with new processes or process modifications. Therefore, vacuum infusion is a term with many acronyms. It cannot always be clearly assigned whether a method is a new process or a modification of existing processes.....
MSc. Thesis Defense:Hafiz Qasim Ali | Experimental Study on Static and Dynamic Behavior of Woven Carbon Fabric Lamınates Using in-House Piezoelectric Sensors, Acoustic Emission, Digital Image Correlation and Scanning Electron Microscopy
MSc. Thesis Defense:Hafiz Qasim Ali | Enerji-Min Experimental Study on Static and Dynamic Behavior of Woven Carbon Fabric Lamınates Using in-House Piezoelectric Sensors, Acoustic Emission, Digital Image Correlation and Scanning Electron Microscopyor
This study focuses on dynamic and static failure analysis of carbon fabric reinforced polymeric composite materials. The first part emphases on the production of Piezoelectric Polyvinylidene fluoride (PVDF) nanofibers-based sensor for structural health monitoring of composites. Results obtained from the characterization of electrospun PVDF nanofibers confirm that electrospinning promotes the formation of β-phase. Dynamic flexural tests are performed on woven carbon fabric composites with embedded and surface mounted PVDF sensors to study the capability of these sensors to record strain history and damage progression in composite materials. Moreover, these PVDF sensors are able to capture three distinct stages of fatigue life of composite specimen. This result is validated by the strain measurement with the video extensometer during tests. It is important to emphasize that surface mounted PVDF sensors do not show any sign of malfunctioning during the test. SEM analysis of fractured surfaces of composite specimens show vivid delamination and fiber pullouts through the thickness, thus indicating gradual growth of damage in laminates. The second part of this study is related to static failure analysis of woven fabric carbon reinforced polymeric composites under tensile and flexural loading. To conduct a detailed investigation Acoustic Emission (AE) is used to attain damage evolution under flexural loading conditions. For the first time GAP function has been suggested to find out the optimal number of clusters for AE data, the advantage of this function is its suitability for classifying elongated data points in vectoral space of acoustic data. Three clusters of data are determined with this new approach indicating various failure types in composite laminates and it is shown that simultaneous occurrence of all failures results in a major change of material stiffness. These failures are also substantiated by Scanning Electron Microscope (SEM) studies of fracture surfaces. Further studies on tensile behavior of the same laminates are conducted with help of SEM micrographs and 3D-digital image correlation (DIC) technique. Remarkably, it is seen that presence of the shear and transverse strain fields at surface of tensile specimen obtained through DIC technique can be correlated to shear dominant and high energy failure (interlaminar delamination and fiber pull outs) respectively, which are also confirmed by SEM images of same fracture regions.
This study focuses on dynamic and static failure analysis of carbon fabric reinforced polymeric composite materials. The first part emphases on the production of Piezoelectric Polyvinylidene fluoride (PVDF) nanofibers-based sensor for structural health monitoring of composites. Results obtained from the characterization of electrospun PVDF nanofibers confirm that electrospinning promotes the formation of β-phase. Dynamic flexural tests are performed on woven carbon fabric composites with embedded and surface mounted PVDF sensors to study the capability of these sensors to record strain history and damage progression in composite materials. Moreover, these PVDF sensors are able to capture three distinct stages of fatigue life of composite specimen. This result is validated by the strain measurement with the video extensometer during tests. It is important to emphasize that surface mounted PVDF sensors do not show any sign of malfunctioning during the test. SEM analysis of fractured surfaces of composite specimens show vivid delamination and fiber pullouts through the thickness, thus indicating gradual growth of damage in laminates. The second part of this study is related to static failure analysis of woven fabric carbon reinforced polymeric composites under tensile and flexural loading. To conduct a detailed investigation Acoustic Emission (AE) is used to attain damage evolution under flexural loading conditions. For the first time GAP function has been suggested to find out the optimal number of clusters for AE data, the advantage of this function is its suitability for classifying elongated data points in vectoral space of acoustic data. Three clusters of data are determined with this new approach indicating various failure types in composite laminates and it is shown that simultaneous occurrence of all failures results in a major change of material stiffness. These failures are also substantiated by Scanning Electron Microscope (SEM) studies of fracture surfaces. Further studies on tensile behavior of the same laminates are conducted with help of SEM micrographs and 3D-digital image correlation (DIC) technique. Remarkably, it is seen that presence of the shear and transverse strain fields at surface of tensile specimen obtained through DIC technique can be correlated to shear dominant and high energy failure (interlaminar delamination and fiber pull outs) respectively, which are also confirmed by SEM images of same fracture regions.
30 août 2019
Une maquette de Notre-Dame de Paris sera réalisée à Felletin par les professionnels de toute la Nouvelle-Aquitaine - Felletin (23500) - La Montagne
Une maquette de Notre-Dame de Paris sera réalisée à Felletin par les professionnels de toute la Nouvelle-Aquitaine - Felletin (23500) - La Montagne
"Le vendredi 13 septembre, au lycée des métiers du bâtiment de Felletin, sera lancée l’école du patrimoine Notre-Dame. Le président Alain Rousset l'a imaginée au lendemain du sinistre qui a ravagé la cathédrale. C'est l'une des composantes du traitement de choc dont bénéficie l'établissement creusois centenaire. Le président de la Nouvelle-Aquitaine définit cette stratégie.
...Nous allons mobiliser les professionnels de tous les corps de métiers capables de candidater à la reconstruction de Notre-Dame-de Paris. Il y aura des charpentiers, des tailleurs de pierre mais aussi desspécialistes des matériaux composites qui seront sollicités pour consolider, par exemple, les arcs-boutants.
"Le vendredi 13 septembre, au lycée des métiers du bâtiment de Felletin, sera lancée l’école du patrimoine Notre-Dame. Le président Alain Rousset l'a imaginée au lendemain du sinistre qui a ravagé la cathédrale. C'est l'une des composantes du traitement de choc dont bénéficie l'établissement creusois centenaire. Le président de la Nouvelle-Aquitaine définit cette stratégie.
...Nous allons mobiliser les professionnels de tous les corps de métiers capables de candidater à la reconstruction de Notre-Dame-de Paris. Il y aura des charpentiers, des tailleurs de pierre mais aussi desspécialistes des matériaux composites qui seront sollicités pour consolider, par exemple, les arcs-boutants.
On va réunir des compagnons du devoir, des PME et des grands groupes, mais aussi tous les centres de formations du bâtiment de la Région, des architectes et des personnalités nationales.
L’objectif, au-delà de la reconstruction du monument, c’est aussi d’apporter aux jeunes de la Région des pistes d’orientation. "
Les actus sur Notre Dame dans le blog, cliquez ici
Les actus sur Notre Dame dans le blog, cliquez ici
#Felletin et son #lycée des métiers du #Bâtiment encore à l'honneur avec l'annonce d'une réalisation d'une maquette de Notre Dame de Paris par les professionnels de Nouvelle Aquitaine...— Françoise AMBIAUX (@franoise7) August 30, 2019
➡️https://t.co/3V0eQE6MCY@RestauronsNDP @LMBFelletin #modélisation #BIM #architecture pic.twitter.com/1YdXXX6AOi
26 août 2019
A review on Graphene Polymer Nanocomposites in Harsh Operating Conditions | Industrial & Engineering Chemistry Research
A review on Graphene Polymer Nanocomposites in Harsh Operating Conditions | Industrial & Engineering Chemistry Research
Development of high-performance composites operating in harsh conditions is gaining tremendous attention due to their broad applications in mass transport, defense, energy, manufacturing, electronics, healthcare, and so forth. Some of the current challenges include the development of lightweight composites suitable for high or low temperatures, high impacts, and corrosive or radiation environments. Among various nanomaterials, graphene based materials have emerged as the most popular class of nanoadditive which can revolutionize every industry sectors. Herein, we briefly discuss the properties of graphene as a prospective additive for high-performance composites. The review focuses on the functional properties of graphene-polymer nanocomposites in a wide range of harsh operational conditions, such as cryo-mechanical properties, ballistic impact resistance, thermal conductivity, deicing/anti-icing behavior, self-cleaning, sensing properties and flame retardant properties. Finally, we conclude with a brief outlook for the development of graphene-polymer nanocomposites for harsh conditions by discussing the major progress, challenges, and opportunities.
Development of high-performance composites operating in harsh conditions is gaining tremendous attention due to their broad applications in mass transport, defense, energy, manufacturing, electronics, healthcare, and so forth. Some of the current challenges include the development of lightweight composites suitable for high or low temperatures, high impacts, and corrosive or radiation environments. Among various nanomaterials, graphene based materials have emerged as the most popular class of nanoadditive which can revolutionize every industry sectors. Herein, we briefly discuss the properties of graphene as a prospective additive for high-performance composites. The review focuses on the functional properties of graphene-polymer nanocomposites in a wide range of harsh operational conditions, such as cryo-mechanical properties, ballistic impact resistance, thermal conductivity, deicing/anti-icing behavior, self-cleaning, sensing properties and flame retardant properties. Finally, we conclude with a brief outlook for the development of graphene-polymer nanocomposites for harsh conditions by discussing the major progress, challenges, and opportunities.
19 août 2019
PHD Characterisation and Exploitation of Ultrasonic Guided Wave Modes for Structural Health Monitoring of Glass-Fibre-Reinforced-Polymer Structures
PHD Characterisation and Exploitation of Ultrasonic Guided Wave Modes for Structural Health Monitoring of Glass-Fibre-Reinforced-Polymer Structures
Recently, great interest has arisen on the application of guided waves on composite materials, owing to the successful results achieved in metallic structures. Due to its more complex nature, guided wave technology for composites is still unmatured, requiring further research to be deployed in commercial structures. The work presented in this thesis focuses on overcoming some of the obstacles for its
deployment, and better understanding uncertainties about its propagation and detection capabilities. Calculation of dispersion curves in composites hinders the use of guided waves, since material properties are not commonly available so existing techniques are unable to calculate them. In this thesis, a new experimental technique is presented for the creation of dispersion curves without requiring any prior knowledge of material properties and being able to be deployed on site.
Recently, great interest has arisen on the application of guided waves on composite materials, owing to the successful results achieved in metallic structures. Due to its more complex nature, guided wave technology for composites is still unmatured, requiring further research to be deployed in commercial structures. The work presented in this thesis focuses on overcoming some of the obstacles for its
deployment, and better understanding uncertainties about its propagation and detection capabilities. Calculation of dispersion curves in composites hinders the use of guided waves, since material properties are not commonly available so existing techniques are unable to calculate them. In this thesis, a new experimental technique is presented for the creation of dispersion curves without requiring any prior knowledge of material properties and being able to be deployed on site.
6 août 2019
WIND TURBINE BLADE WITH IMPROVED GLUE JOINT AND RELATED METHOD - LM WIND POWER US TECHNOLOGY APS
WIND TURBINE BLADE WITH IMPROVED GLUE JOINT AND RELATED METHOD - LM WIND POWER US TECHNOLOGY APS
A blade shell part for a wind turbine blade and a wind turbine blade are disclosed. The blade shell part is made of a composite structure comprising a reinforcement material embedded in a polymer matrix, the blade shell part extending from a tip end to a root end, wherein the blade shell part comprises: a blade shell body with a leading edge and a trailing edge, and a first glue flange extending from the leading edge and having a first glue flange edge and a first glue surface with a first width, wherein the first glue flange is provided with one or more spacer elements. Further, a method of manufacturing a wind turbine blade is described.
A blade shell part for a wind turbine blade and a wind turbine blade are disclosed. The blade shell part is made of a composite structure comprising a reinforcement material embedded in a polymer matrix, the blade shell part extending from a tip end to a root end, wherein the blade shell part comprises: a blade shell body with a leading edge and a trailing edge, and a first glue flange extending from the leading edge and having a first glue flange edge and a first glue surface with a first width, wherein the first glue flange is provided with one or more spacer elements. Further, a method of manufacturing a wind turbine blade is described.
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