Download or read book Advances in composite wind turbine blades A comparative study written by Adam Chehouri and published by diplom.de. This book was released on 2014-03-01 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the wind industry, the current trend is towards building larger and larger turbines. This presents additional structural challenges and requires blade materials that are both lighter and stiffer than the ones presently used. This study is aimed to aid the work of designing new wind turbine blades by providing a comparative study of different composite materials. A coupled Finite-Element-Method (FEM) - Blade Element Momentum (BEM) code was used to simulate the aerodynamic forces subjected on the blade. For this study, the finite element study was conducted on the Static Structural Workbench of ANSYS, as for the geometry of the blade it was imported from a previous study prepared by Cornell University. Confirmation of the performance analysis of the chosen wind turbine blade is presented and discussed including the generated power, tip deflection, thrust and tangential force for a steady flow of 8m/s. A homogenization method was applied to derive the mechanical properties and ultimate strengths of the composites. The Tsai-Hill and Hoffman failure criterions were both conducted to the resulting stresses and shears for each blade composite material structure to determine the presence of static rupture. A progressive fatigue damage model was conducted to simulate the fatigue behavior of laminated composite materials, an algorithm developed by Shokrieh.

Download or read book Advances in Composite Wind Turbine Blades A Comparative Study written by Adam Chehouri and published by Anchor Academic Publishing (aap_verlag). This book was released on 2014-03-19 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the wind industry, the current trend is towards building larger and larger turbines. This presents additional structural challenges and requires blade materials that are both lighter and stiffer than the ones presently used. This study is aimed to aid the work of designing new wind turbine blades by providing a comparative study of different composite materials. A coupled Finite-Element-Method (FEM) - Blade Element Momentum (BEM) code was used to simulate the aerodynamic forces subjected on the blade. For this study, the finite element study was conducted on the Static Structural Workbench of ANSYS, as for the geometry of the blade it was imported from a previous study prepared by Cornell University. Confirmation of the performance analysis of the chosen wind turbine blade is presented and discussed including the generated power, tip deflection, thrust and tangential force for a steady flow of 8m/s. A homogenization method was applied to derive the mechanical properties and ultimate strengths of the composites. The Tsai-Hill and Hoffman failure criterions were both conducted to the resulting stresses and shears for each blade composite material structure to determine the presence of static rupture. A progressive fatigue damage model was conducted to simulate the fatigue behavior of laminated composite materials, an algorithm developed by Shokrieh.

Download or read book Advances in Wind Turbine Blade Design and Materials written by Povl Brondsted and published by Elsevier. This book was released on 2013-10-31 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind energy is gaining critical ground in the area of renewable energy, with wind energy being predicted to provide up to 8% of the world’s consumption of electricity by 2021. Advances in wind turbine blade design and materials reviews the design and functionality of wind turbine rotor blades as well as the requirements and challenges for composite materials used in both current and future designs of wind turbine blades. Part one outlines the challenges and developments in wind turbine blade design, including aerodynamic and aeroelastic design features, fatigue loads on wind turbine blades, and characteristics of wind turbine blade airfoils. Part two discusses the fatigue behavior of composite wind turbine blades, including the micromechanical modelling and fatigue life prediction of wind turbine blade composite materials, and the effects of resin and reinforcement variations on the fatigue resistance of wind turbine blades. The final part of the book describes advances in wind turbine blade materials, development and testing, including biobased composites, surface protection and coatings, structural performance testing and the design, manufacture and testing of small wind turbine blades. Advances in wind turbine blade design and materials offers a comprehensive review of the recent advances and challenges encountered in wind turbine blade materials and design, and will provide an invaluable reference for researchers and innovators in the field of wind energy production, including materials scientists and engineers, wind turbine blade manufacturers and maintenance technicians, scientists, researchers and academics. Reviews the design and functionality of wind turbine rotor blades Examines the requirements and challenges for composite materials used in both current and future designs of wind turbine blades Provides an invaluable reference for researchers and innovators in the field of wind energy production

Download or read book A Comparative Study of Static and Fatigue Behaviors for Various Composite Orthotropic Properties for a Wind Turbine Using a Coupled FEM BEM Method written by Adam Chehouri and published by GRIN Verlag. This book was released on 2014-01-13 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2013 in the subject Engineering - Mechanical Engineering, grade: 4.06/4.5 GPa, , language: English, abstract: In the wind industry, the current trend is towards building larger and larger turbines. This presents additional structural challenges and requires blade materials that are both lighter and stiffer than the ones presently used. This work is aimed to aid the work of designing new wind turbine blades by providing a comparative study of different composite materials. A coupled Finite-Element-Method (FEM) - Blade Element Momentum (BEM) code was used to simulate the aerodynamic forces subjected on the blade. The developed BEM code was written using LabView allowing an iterative numerical approach solver taking into the consideration the unsteady aerodynamic effects and off –design performance issues such as Tip Loss, Hub Loss and Turbulent Wake State therefore developing a more rational aerodynamic model. For this thesis, the finite element study was conducted on the Static Structural Workbench of ANSYS, as for the geometry of the blade it was imported from a previous study prepared by Cornell University. Confirmation of the performance analysis of the chosen wind turbine blade are presented and discussed blade including the generated power, tip deflection, thrust and tangential force for a steady flow of 8m/s. The elastic and ultimate strength properties were provided by Hallal et al. The Tsai- Hill and Hoffman failure criterions were both conducted to the resulting stresses and shears for each blade composite material structure to determine the presence of static rupture. A progressive fatigue damage model was conducted to simulate the fatigue behavior of laminated composite materials, an algorithm developed by Shokrieh. It is concluded that with respect to a material blade design cycle, the coupling between a finite element package and blade element and momentum code under steady and static conditions can be useful. Especially when an integration between this coupled approach and a dynamic simulation tool could be established, a more advanced flexible blade design can be then analyzed for a novel generation of more flexible wind turbine blades.

Download or read book Advances in wind turbine blade design and materials written by B. Madsen and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter about biobased composites starts by presenting the most promising types of cellulose fibres; their properties, processing and preforms for composites, together with an introduction to biobased matrix materials. The chapter then presents the typical mechanical properties of biobased composites, based on examples of composites with different fibre/matrix combinations, followed by a case study of the stiffness and specific stiffness of cellulose fibre composites vs glass fibre composites using micromechanical model calculations. Finally, the chapter presents some of the special considerations to be addressed in the development and application of biobased composites.

Download or read book Advances in wind turbine blade design and materials written by R.P.L. Nijssen and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composites have been the material of choice for wind turbine blade construction for several decades. This chapter explains why. It also shows how wind turbine blade materials and our understanding of their fatigue behaviour have developed recently, and the gaps that still exist in the knowledge. The chapter discusses why fatigue is a predominant design driver for wind turbine blades. The main structural elements of the blade (load bearing components and aerodynamic shell) are considered in terms of material and design requirements, and fundamental research questions are addressed. Finally, there is a comment on current and future trends, as well as a list of recommended reading.

Download or read book Advances in wind turbine blade design and materials written by D.J. Lekou and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chapter discusses the topic of probabilistic analysis of wind turbine blades. First, structural analysis models, the definition of ‘failure’ and the treatment of random variables will be explored, focusing on the challenges involved in a probabilistic design depending on the choices made during each step. Next, the various probabilistic methods (Monte Carlo method, first-order reliability method, Edgeworth expansion method, response surface method) will be described. Issues arising out of the use of composite material structures, in applications such as wind turbine blades, as well as other aspects relating to wind energy applications will be highlighted, and techniques will be discussed through examples.

Download or read book Advances in wind turbine blade design and materials written by F. Mølholt Jensen and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the current and future trends in wind turbine blade structural design process is presented. The main design principles and failure mechanisms of blades in operation are assessed and explained through an industry point of view, in a realistic manner. A number of failure modes which are not addressed sufficiently in the certificate guidelines are presented. An example on how to use the new design philosophy is presented. The manufactured prototype is a 44m long load carrying spar and the weight is reduced by 40%.

Download or read book Advances in wind turbine blade design and materials written by P.D. Clausen and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small wind turbine blades share a number of features with large blades, but have some important differences. The two main differences are their much higher rotational speed, which causes more fatigue cycles and higher yaw moments, and their operation at low Reynolds number, which means that thick aerofoil sections cannot be used near the root. This chapter discusses the design challenges arising from these differences, the materials commonly used for blade manufacture, and the fatigue testing of small blades. The use of timber is highlighted for very small blades, and fibre-reinforced composite manufacture of larger ones is discussed in terms of sustainability, conformity of manufactured shape, and fatigue behaviour.

Download or read book Advances in wind turbine blade design and materials written by L. MISHNAEVSKY and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the micromechanics of materials methods and approaches that can be used for the modelling of wind turbine blade composites is given in this chapter. Using the various modelling methods reviewed here, the strength, stiffness and lifetime of composite materials can be predicted and the suitability of different groups of materials for applications in wind turbine blades can be analysed. The effects of interface and matrix properties, fibre clustering and nanoreinforcement on the strength and lifetime of composites are studied in a number of simulations, and some examples of the analysis of microstructural effects on the strength and fatigue life of composites are provided.

Download or read book MARE WINT written by Wiesław Ostachowicz and published by Springer. This book was released on 2016-08-30 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a holistic, interdisciplinary overview of offshore wind energy, and is a must-read for advanced researchers. Topics, from the design and analysis of future turbines, to the decommissioning of wind farms, are covered. The scope of the work ranges from analytical, numerical and experimental advancements in structural and fluid mechanics, to novel developments in risk, safety & reliability engineering for offshore wind.The core objective of the current work is to make offshore wind energy more competitive, by improving the reliability, and operations and maintenance (O&M) strategies of wind turbines. The research was carried out under the auspices of the EU-funded project, MARE-WINT. The project provided a unique opportunity for a group of researchers to work closely together, undergo multidisciplinary doctoral training, and conduct research in the area of offshore wind energy generation. Contributions from expert, external authors are also included, and the complete work seeks to bridge the gap between research and a rapidly-evolving industry.

Download or read book Advances in wind turbine blade design and materials written by A.P. Vassilopoulos and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue life prediction of wind turbine rotor blades is a very challenging task, as blade failure is led by different failure types that act synergistically. Inherent defects like wrinkles, fiber misalignments and voids, that can be introduced during fabrication, can constitute potential damage initiation points and rapidly develop to failure mechanisms like matrix cracking, transverse-ply cracking, interface cracking, debonding, fiber breakage, etc. Different methods have been established to address this problem, some based on phenomenological and others on actual damage mechanics modeling. This chapter aims to provide an overview of fatigue life modeling and prediction methodologies for the composite materials and structural composite elements that compose a wind turbine rotor blade under complex loading conditions.

Download or read book Advanced Composite Wind Turbine Blade Design Based on Durability and Damage Tolerance written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints and closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D & DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique (VCCT) PFA while the second one is strength-based. Constituent stiffness and strength properties for glass and carbon based material systems were reverse engineered for use in D & DT evaluation of coupons with ply drops under static loading. Lamina and laminate properties calculated using manufacturing and composite architecture details matched closely published test data. Similarly, resin properties were determined for fatigue life calculation. The simulation not only reproduced static strength and fatigue life as observed in the test, it also showed composite damage and fracture modes that resemble those reported in the tests. The results show that computational simulation can be relied on to enhance the design of tapered composite structures such as the ones used in turbine wind blades. A computational simulation for durability, damage tolerance (D & DT) and reliability of composite wind turbine blade structures in presence of uncertainties in material properties was performed. A composite turbine blade was first assessed with finite element based multi-scale progressive failure analysis to determine failure modes and locations as well as the fracture load. D & DT analyses were then validated with static test performed at Sandia National Laboratories. The work was followed by detailed weight analysis to identify contribution of various materials to the overall weight of the blade. The methodology ensured that certain types of failure modes, such as delamination progression, are contained to reduce risk to the structure. Probabilistic analysis indicated that composite shear strength has a great influence on the blade ultimate load under static loading. Weight was reduced by 12% with robust design without loss in reliability or D & DT. Structural benefits obtained with the use of enhanced matrix properties through nanoparticles infusion were also assessed. Thin unidirectional fiberglass layers enriched with silica nanoparticles were applied to the outer surfaces of a wind blade to improve its overall structural performance and durability. The wind blade was a 9-meter prototype structure manufactured and tested subject to three saddle static loading at Sandia National Laboratory (SNL). The blade manufacturing did not include the use of any nano-material. With silica nanoparticles in glass composite applied to the exterior surfaces of the blade, the durability and damage tolerance (D & DT) results from multi-scale PFA showed an increase in ultimate load of the blade by 9.2% as compared to baseline structural performance (without nan ...

Download or read book Advances in wind turbine blade design and materials written by J. G.Holierhoek and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeroelasticity concerns the interaction between aerodynamics, dynamics and elasticity. This interaction can result in negatively or badly damped wind turbine blade modes, which can have a significant effect on the turbine lifetime. The first aeroelastic problem that occurred on commercial wind turbines concerned a negatively damped edgewise mode. It is important to ensure that there is some out-of-plane deformation in this mode shape to prevent the instability. For larger turbine blades with lower torsional stiffness and the possibility of higher tip speeds for the offshore designs, classical flutter could also become relevant. When designing a wind turbine blade, it is therefore crucial that there is enough damping for the different modes and that there is no coincidence of natural frequencies with excitation frequencies (resonance). An effective aeroelastic analysis is also important, and the tools used for such an analysis must include the necessary detail in the structural model.

Download or read book Structural Analysis of Composite Wind Turbine Blades written by Dimitris I Chortis and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book concerns the development of novel finite elements for the structural analysis of composite beams and blades. The introduction of material damping is also an important aspect of composite structures and it is presented here in terms of their static and dynamic behavior. The book thoroughly presents a new shear beam finite element, which entails new blade section mechanics, capable of predicting structural blade coupling due to composite coupling and/or internal section geometry. Theoretical background is further expanded towards the inclusion of nonlinear structural blade models and damping mechanics for composite structures. The models effectively include geometrically nonlinear terms due to large displacements and rotations, improve the modeling accuracy of very large flexible blades, and enable the modeling of rotational stiffening and buckling, as well as, nonlinear structural coupling. Validation simulations on specimen level study the geometric nonlinearities effect on the modal frequencies and damping values of composite strips of various angle-ply laminations under either tensile or buckling loading. A series of correlation cases between numerical predictions and experimental measurements give credence to the developed nonlinear beam finite element models and underline the essential role of new nonlinear damping and stiffness terms.

Download or read book Advances in Wind Turbine Blade Design and Materials written by Povl Brondsted and published by Woodhead Publishing. This book was released on 2023-01-14 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Wind Turbine Blade Design and Materials, Second Edition, builds on the thorough review of the design and functionality of wind turbine rotor blades and the requirements and challenges for composite materials used in both current and future designs of wind turbine blades. Reviews the design and functionality of wind turbine rotor blades Examines the requirements and challenges for composite materials used in both current and future designs of wind turbine blades Provides an invaluable reference for researchers and innovators in the field of wind

Download or read book Advances in wind turbine blade design and materials written by J.F. Mandell and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter explores the influence of resin and reinforcing fabric variations on the fatigue sensitivity for a wide range of typical blade laminates reported recently in the SNL/MSU/DOE database. Test results are presented for static and fatigue property variations with resin type, reinforcing fabric construction and weight, fiber content and laminate construction. Critical resin/fabric interactions and damage mechanisms are identified. The effects of resin and fiber type are also explored for material transitions at ply drops, where ply delamination is the dominant damage.