Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Comparative Analysis Of Transient Dynamics Of Large Scale Offshore Wind Turbines With Different Foundation Structure Under Seismic
Download Comparative Analysis Of Transient Dynamics Of Large Scale Offshore Wind Turbines With Different Foundation Structure Under Seismic full books in PDF, epub, and Kindle. Read online Comparative Analysis Of Transient Dynamics Of Large Scale Offshore Wind Turbines With Different Foundation Structure Under Seismic ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Comparative Analysis of Transient Dynamics of Large-Scale Offshore Wind Turbines with Different Foundation Structure Under Seismic by : Minnan Yue
Download or read book Comparative Analysis of Transient Dynamics of Large-Scale Offshore Wind Turbines with Different Foundation Structure Under Seismic written by Minnan Yue and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, a structural dynamic response comparison between jacket foundation large-scale offshore wind turbines (OWTs) and monopile ones under wind and seismic loads is demonstrated. The interaction between flexible soil and pile foundation is described by Winkler soil-structure interaction (SSI) model. The National Renewable Energy Laboratory (NREL) 5 MW large-scale OWT is studied via the finite element model. The structural transient dynamic response of these two structures under normal operating conditions at rated wind speed and earthquake is calculated. The results show that under the action of seismic and turbulent wind, the jacket has better wind and seismic resistance, and the displacement of the top of the tower is small, which can effectively protect the blades and the nacelle. Compared with monopile, the range of the Mises equivalent stress amplitude of the jacket wind turbine was reduced and the average value was decreased at the time of the seismic. The study also found that the existing jacket design will have a local strain energy surge.
Book Synopsis A Comparison of Alternative Foundation Models for Offshore Wind Turbines and Resulting Long-term Loads by : Erica Angelyn Bush
Download or read book A Comparison of Alternative Foundation Models for Offshore Wind Turbines and Resulting Long-term Loads written by Erica Angelyn Bush and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate estimation of structural design loads for wind turbines can help improve cost-effectiveness of wind energy. This study concentrates on predicting long-term characteristic loads for a single design load case for offshore wind turbines associated with an ultimate limit state. Specifically, we study how alternative foundation modeling assumptions and load variability can influence characteristic tower and blade load estimates needed in design. Six foundation models with varying degrees of complexity are compared for a utility-scale 5MW offshore wind turbine. The fixed base model does not account for soil-pile interaction. The apparent fixity model, the modified apparent fixity model, the coupled springs model, and the distributed springs model account for soil-pile interaction by linearizing the lateral stiffness, while the p-y curves model accounts for soil-pile interaction by incorporating the nonlinear response. Accounting for soil-pile flexibility allows the wind turbine model to have similar dynamic characteristics as the true structure. This study shows that accurate structural dynamics is required to produce accurate long-term tower loads, but not necessarily accurate long-term blade loads. All foundation models, including the fixed base model, are shown sufficient for predicting long-term blade load estimates, but flexible foundation models are needed to predict long-term tower loads. We show that linear and nonlinear flexible foundation models are fairly interchangeable for predicting long-term loads for our environmental conditions, wind turbine, and sand profiles because deflections generally stay in the initial quasi-linear range of the p-y curves. In this study, we extrapolate long-term loads using 2D inverse first-order reliability method (FORM) and 3D inverse FORM. The 3D inverse FORM approach accounts for the variability in the load, while the 2D inverse FORM approach does not. We show that characteristic tower and blade loads are strongly influenced by load variability and suggest that it be considered in any effort to predict characteristic long-term loads for design of offshore wind turbines.
Book Synopsis Design of Foundations for Offshore Wind Turbines by : Subhamoy Bhattacharya
Download or read book Design of Foundations for Offshore Wind Turbines written by Subhamoy Bhattacharya and published by John Wiley & Sons. This book was released on 2019-04-29 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive reference covering the design of foundations for offshore wind turbines As the demand for “green” energy increases the offshore wind power industry is expanding at a rapid pace around the world. Design of Foundations for Offshore Wind Turbines is a comprehensive reference which covers the design of foundations for offshore wind turbines, and includes examples and case studies. It provides an overview of a wind farm and a wind turbine structure, and examines the different types of loads on the offshore wind turbine structure. Foundation design considerations and the necessary calculations are also covered. The geotechnical site investigation and soil behavior/soil structure interaction are discussed, and the final chapter takes a case study of a wind turbine and demonstrates how to carry out step by step calculations. Key features: New, important subject to the industry. Includes calculations and case studies. Accompanied by a website hosting software and data files. Design of Foundations for Offshore Wind Turbines is a must have reference for engineers within the renewable energy industry and is also a useful guide for graduate students in this area.
Author :National Research Council (U.S.). Committee on Offshore Wind Energy Turbine Structural and Operating Safety Publisher :Transportation Research Board ISBN 13 :0309160820 Total Pages :194 pages Book Rating :4.3/5 (91 download)
Book Synopsis Structural Integrity of Offshore Wind Turbines: Oversight of Design, Fabrication, and Installation by : National Research Council (U.S.). Committee on Offshore Wind Energy Turbine Structural and Operating Safety
Download or read book Structural Integrity of Offshore Wind Turbines: Oversight of Design, Fabrication, and Installation written by National Research Council (U.S.). Committee on Offshore Wind Energy Turbine Structural and Operating Safety and published by Transportation Research Board. This book was released on 2011-09-02 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The U.S. Department of the Interior's Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) is responsible for the orderly, safe, and environmentally responsible development of offshore renewable energy on the outer continental shelf (OCS). The Committee on Offshore Wind Energy Turbine Structural and Operating Safety that authored this report was tasked with reviewing BOEMRE's proposed approach to overseeing the design of offshore wind turbines for structural integrity. The committee was asked to review the applicability and adequacy of standards and practices that could be used for the design, fabrication and installation of offshore wind turbines. It was also asked to review the role of third-party certified verification agents (CVAs) and the expertise and qualifications needed to carry out the role of a CVA. The committee's findings are presented in the following chapters: (1) Introduction; (2) Offshore Wind Technology and Status; (3) Standards and Practices; (4) A Risk-Informed Approach to Performance Assurance; (5) Role of Third-Party Oversight and Certified Verification Agents; (6) Qualifications Needed by Certified Verification Agents; and (7) Summary of Key Findings and Recommendations."--Pub. desc.
Book Synopsis A comparison of methods for computation of wave forcing by : Olga Glöckner
Download or read book A comparison of methods for computation of wave forcing written by Olga Glöckner and published by GRIN Verlag. This book was released on 2018-05-17 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diploma Thesis from the year 2014 in the subject Engineering - Civil Engineering, grade: 1,0, University of Hannover (A&M University Texas, Ludwig-Franzius-Institut für Wasserbau, Ästuar- und Küsteningenieurwesen), language: English, abstract: Unlike fossil fuels (for example oil, coal and natural gas), wind energy is a renewable energy resource. Since winds at sea are stronger and more consistent than onshore winds, the demand for offshore wind turbines has increased over the last years. As energy can be produced more efficient in deeper water, several floating offshore wind turbine constructions, such as the OC3 Hywind spar-buoy, have been proposed. The design of floating wind turbines depends on the simulation of the system behavior caused by exciting forces. This thesis deals with the comparison between different methods for calculating wave forces and resulting platform motions of a floating offshore wind turbine. On the one hand, wave exciting loads computed with Morison’s equation are compared to the hydrodynamic forces simulated by the open source code FAST on the basis of the diffraction theory. On the other hand, response motions of the floating structure are simulated by the commercial offshore software SESAM in the frequency domain and compared with the motions calculated by FAST in the time domain.
Book Synopsis Experimental and Numerical Seismic Response of Offshore Wind Turbines Supported on Bucket Foundations by : Muhammad Zayed
Download or read book Experimental and Numerical Seismic Response of Offshore Wind Turbines Supported on Bucket Foundations written by Muhammad Zayed and published by . This book was released on 2022 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bucket foundations have proven to be an efficient cost-effective option for a wide range of offshore applications. Motivated by the strong growth in offshore wind energy, this dissertation aims to investigate the seismic response of bucket foundations. A scaled soil-structure model of a 3.45 Megawatt (MW) utility-scale Offshore Wind Turbine (OWT) was tested on medium-size 1-g shake table. A preliminary testing phase resulted in developing new approaches for: i) tracking shear wave velocity variation within the ground during seismic excitation, and ii) generating accumulated ground deformation via asymmetric base shaking. Thereafter, the OWT model was subjected to a series of harmonic and earthquake-like excitations. From the collected data, key features of the overall system response were gleaned. Utilizing the experimental data, a nonlinear finite element (FE) model was calibrated to simulate the observed seismic response. The developed FE model was then extended to investigate the seismic behavior of a representative utility-scale OWT in sands under earthquake motions, combined with operational wind load effects. A parametric study is conducted to investigate influence of: i) soil stiffness and strength, ii) ground motion characteristics, iii) soil permeability, iv) bucket size, and v) damping on the OWT seismic response. The results suggest that: i) the near field pore water pressure build-up and bucket rotation are correlated, ii) ground motion characteristics have direct impact on the permanent bucket rotation, iii) lower soil permeability results in larger rotation due to the higher near field pore water pressure build-up, iv) permanent bucket rotation tends to reach a maximum and a minimum at the lower and upper bounds of soil permeability, respectively, reflecting the fully drained and undrained conditions, v) the difference in permanent bucket rotation between undrained and drained conditions tends to decrease with increasing soil stiffness, vi) Within the range of investigated scenarios, an essentially linear correlation was noted between the OWT fundamental frequency and the permanent bucket rotation, and vii) viscous damping at higher frequencies might have a significant effect on the bucket moment rotation response. As such, the gained insights provide guidance for seismic design of bucket foundation offshore wind turbines.
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.
Book Synopsis Topics in Experimental Dynamics Substructuring and Wind Turbine Dynamics, Volume 2 by : R. Mayes
Download or read book Topics in Experimental Dynamics Substructuring and Wind Turbine Dynamics, Volume 2 written by R. Mayes and published by Springer Science & Business Media. This book was released on 2012-04-11 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topics in Experimental Dynamics Substructuring and Wind Turbine Dynamics, Volume 2, Proceedings of the 30th IMAC, A Conference and Exposition on Structural Dynamics, 2012, the second volume of six from the Conference, brings together 31 contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Advances in Structural Engineering by : Vasant Matsagar
Download or read book Advances in Structural Engineering written by Vasant Matsagar and published by Springer. This book was released on 2014-12-12 with total page 1033 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents research papers presented by academicians, researchers, and practicing structural engineers from India and abroad in the recently held Structural Engineering Convention (SEC) 2014 at Indian Institute of Technology Delhi during 22 – 24 December 2014. The book is divided into three volumes and encompasses multidisciplinary areas within structural engineering, such as earthquake engineering and structural dynamics, structural mechanics, finite element methods, structural vibration control, advanced cementitious and composite materials, bridge engineering, and soil-structure interaction. Advances in Structural Engineering is a useful reference material for structural engineering fraternity including undergraduate and postgraduate students, academicians, researchers and practicing engineers.
Book Synopsis Impact of Sea Ice Loads on Global Dynamics of Offshore Wind Turbines by : Wojciech Popko
Download or read book Impact of Sea Ice Loads on Global Dynamics of Offshore Wind Turbines written by Wojciech Popko and published by Fraunhofer Verlag. This book was released on 2020-12-10 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Support structures for offshore wind turbines (OWTs) are designed and certified site-specific based on the calculated load effects. These load effects originate from static, cyclic, stochastic, and transient loads from the met-ocean environment and rotating components of the wind turbine. The met-ocean environment of the Baltic Sea accounts for variable wind and marine conditions. Sea ice is part of marine conditions - which among others - should be included in the design process of OWT support structures. The load analysis and design of OWTs, including its components, rely on the time-domain based, coupled aero-hydro-servo-elastic simulation tools. Only this approach can provide an accurate prediction of the OWT dynamic response. Dynamic interaction between an OWT and external loads - including ice loads - cannot be disregarded as it may result in considerable loss of accuracy. A proper understanding of sea ice impact on the global dynamics of OWTs - involving the fully-integrated simulation approach - is necessary within the offshore wind research community, industry, and certification authorities.
Book Synopsis Dynamic Analysis of an Offshore Wind Turbine Taking Into Account the Soil-foundation-structure Interaction by : Philip Alkhoury
Download or read book Dynamic Analysis of an Offshore Wind Turbine Taking Into Account the Soil-foundation-structure Interaction written by Philip Alkhoury and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind energy has received a vast attention in recent years. Multi-megawatt offshore wind turbines (OWTs) mounted on large diameter monopiles are being widely used nowadays in practice. There is a general acceptance that the overall weight of OWTs must be kept to a minimum to reduce their cost. This eventually resulted in a highly flexible slender structure that is dynamically-sensitive. The high sensitivity to the highly variable external loads demands special design consideration regarding the natural frequency of the OWT system which must be outside the excitations frequencies to avoid resonance. In addition to the resonance avoidance criterion, OWTs must verify stringent serviceability design requirements during their lifetime, which demand the consideration of a reliable numerical tool with an advanced soil constitutive model for the computation of the OWT dynamic responses. Modal and dynamic analyses of such complicated structures have been well-covered in literature using different aeroelastic simulation tools based on a limited number of degrees of freedom and/or make use of simplified assumptions related to the OWT superstructure, the soil-foundation interaction and the soil behavior. In response to these challenges, this thesis presents a three-dimensional finite element (FE) model that reflects the OWT behavior to a high degree of accuracy and that is used for the computation of the OWT modal and dynamic responses. Another aim of this thesis is to study the excessive vibration mitigation of OWTs. In this regard, this thesis presents a novel technique in which FE analysis is combined with a control system to study the real-time performance of an active tuned mass damper in reducing the OWT vibrations.
Book Synopsis An Experimental and Numerical Study of Wind Turbine Seismic Behavior by : Ian Prowell
Download or read book An Experimental and Numerical Study of Wind Turbine Seismic Behavior written by Ian Prowell and published by . This book was released on 2011 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents an experimental and numerical investigation into the seismic response of modern wind turbines. Currently, no consensus exists in the industry and there is significant interest in improving prediction of the behavior of wind turbines simultaneously subjected to wind, earthquake, and operational excitation. To this end, an experimental program was planned in order to evaluate seismic loading of wind turbines. In 2004, a preliminary shake table test of a 65-kW utility scale wind turbine was conducted that provided an experimental basis to begin the work discussed herein. A monitoring campaign was performed at Oak Creek Energy Systems in Mojave, California to assess variability of in-situ dynamic characteristics of two modern wind turbines (900-kW and 1.5-MW rated power) under different operational states and wind conditions. A second shake table experiment with a more extensive test program and improved instrumentation was executed, in which orientation of shaking and operational state were found to significantly influence response. Using the finite element program OpenSees, beam-column models of the tested specimens were constructed and calibrated. Collected data provided a basis to show that such a model could reproduce salient characteristics including natural frequencies, mode shapes, and dynamic response time histories for a parked turbine. In-situ results were used to guide construction of full turbine-foundation-soil models that provided insight into soil-structure interaction phenomena. An existing tool to simulate turbine dynamics, the FAST code, was extended to include seismic loading to allow simulation of operational turbines subjected to base shaking and validated based on shake table results. Using a calibrated model of the tested 900-kW turbine it is shown that neglecting aerodynamics results in significant over estimation of the tower bending demand. An investigation of turbines ranging from 65-kW to 5-MW concluded that consideration of aerodynamics and operational state becomes increasingly important with size. The updated FAST code was demonstrated to accurately reproduce observed dynamics of operating turbines, providing a validated tool for seismic design of turbines. These contributions clarify that operational state and orientation of shaking are important considerations and enable the development of a new generation of turbines that appropriately consider seismic loads.
Book Synopsis Wind Energy Handbook by : Tony Burton
Download or read book Wind Energy Handbook written by Tony Burton and published by John Wiley & Sons. This book was released on 2001-12-12 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: As environmental concerns have focused attention on the generation of electricity from clean and renewable sources wind energy has become the world's fastest growing energy source. The Wind Energy Handbook draws on the authors' collective industrial and academic experience to highlight the interdisciplinary nature of wind energy research and provide a comprehensive treatment of wind energy for electricity generation. Features include: An authoritative overview of wind turbine technology and wind farm design and development In-depth examination of the aerodynamics and performance of land-based horizontal axis wind turbines A survey of alternative machine architectures and an introduction to the design of the key components Description of the wind resource in terms of wind speed frequency distribution and the structure of turbulence Coverage of site wind speed prediction techniques Discussions of wind farm siting constraints and the assessment of environmental impact The integration of wind farms into the electrical power system, including power quality and system stability Functions of wind turbine controllers and design and analysis techniques With coverage ranging from practical concerns about component design to the economic importance of sustainable power sources, the Wind Energy Handbook will be an asset to engineers, turbine designers, wind energy consultants and graduate engineering students.
Book Synopsis Soil-structure Interaction Analysis of Monopile Foundations Supporting Offshore Wind Turbines by : Bipin Kumar Gupta
Download or read book Soil-structure Interaction Analysis of Monopile Foundations Supporting Offshore Wind Turbines written by Bipin Kumar Gupta and published by . This book was released on 2018 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monopile foundations supporting offshore wind turbines are hollow circular steel piles of diameter 4-6 m and a slenderness ratio (length/radius) of 10-12 driven into the seabed in an average water depth of 35 m. They are subjected to large lateral forces and overturning moments at the seabed level from wind, waves, and water currents acting on the wind turbine structure. Currently, they are designed using the p-y analysis method (p is the soil reaction force per unit length at any point along the pile shaft and y is the corresponding pile displacement at that point) which has a number of shortcomings. The p-y analysis was originally developed from a few full-scale field pile-load tests on small-diameter piles (less than 2 m in diameter) and their applicability to large-diameter monopiles is questionable. Besides, it is empirical, site-specific, and does not account for the three-dimensional pile-soil interaction important for large-diameter monopiles, thereby, resulting in a conservative design and an increase in the cost of the project. Three-dimensional finite element analysis can be used for the analysis and design of monopiles, but such analyses require significantly large computational time and effort besides, the specific expertise of finite element software that further limits its use in practice. The primary objective of this thesis is to develop a computationally efficient continuum-based mathematical model that takes the three-dimensional monopile-soil interaction into account. In the thesis, three tasks are performed towards the development of the mathematical model. First, a mathematical framework is developed to analyze laterally loaded monopiles following the Timoshenko beam theory in a multilayered elastic soil deposit subjected to static lateral loading. In the analysis, it is shown that successive simplification of the analysis can lead to monopiles modeled as a Euler-Bernoulli and rigid beam. The analysis is verified with finite element solutions and the suitability of the application each of the beam theories to obtain monopile response (head-displacement and rotation) is also investigated besides, a comparison of the computational time between the present analysis and finite element analysis is also shown. In the second task, the aforementioned framework is extended to analyze monopiles embedded in a multilayered linear viscoelastic soil deposit with frequency-independent hysteretic material damping subjected to harmonic dynamic lateral loading. It is shown that the analysis can be reduced to model monopiles following the Rayleigh, Euler-Bernoulli, and rigid beam theory. The analysis is verified with well-established solution techniques reported in the literature. Further, the results and the computational time obtained from this analysis are compared with those of the analysis in the first task for four different monopiles with varying slenderness ratio currently installed in the field. The purpose of the comparison is to investigate the applicability of the dynamic analysis for obtaining monopile response which is subjected to cyclic loadings of frequency less than 1.0 Hz. It is found that the static analysis following the Euler-Bernoulli beam theory is sufficient for obtaining monopile response. In the third task, the mathematical framework developed in the first task is extended to analyze laterally loaded monopiles modeled as a Euler-Bernoulli beam in a multilayered nonlinear elastic soil deposit and subjected to static loading. In the analysis, the nonlinear elastic relationships describing the variation of shear modulus with shear strain reported in the literature either applicable to undrained clays or sandy soil deposits are utilized. The mathematical accuracy of the analysis is verified by comparing results obtained from the analysis with the results of finite element analysis. A comparison of the computational time between the present and finite element analysis is also shown to demonstrate the computational efficiency of the present analysis. The results of the analysis are further validated with the results of several full-scale field pile-load tests and the p-y analysis procedure available in the literature. The accuracy of the results from this nonlinear elastic approach is further ensured by comparing monopile response with those of finite element simulations where the soil is modeled using an elastic-plastic constitutive model. A comparison of the monopile response is also shown in the p-y analysis to investigate the appropriateness of the currently used p-y curves to analyze and design monopiles. Finally, a preliminary step-by-step design procedure for monopile foundations embedded in nonlinear elastic soil deposit is developed following the recommendations outlined in current codes of practice for offshore wind turbines.
Book Synopsis Nonlinear Dynamics of Compliant Offshore Structures by : Patrick Bar-Avi
Download or read book Nonlinear Dynamics of Compliant Offshore Structures written by Patrick Bar-Avi and published by Routledge. This book was released on 2017-12-04 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph provides a general background to the modelling of a special class of offshore structures known as compliant structures. External forcing is resisted by buoyancy and tension forces which increase when the structure is slightly offset from its equilibrium. The technical development given in this book is presented in such a way as to highlight the adaptability of the modelling, and the reader is shown how the techniques described can be applied to a variety of different offshore structures.
Book Synopsis Design and Analysis of Suction Pile-based Large-scale Offshore Wind Turbines Under Earthquakes and Typhoons by :
Download or read book Design and Analysis of Suction Pile-based Large-scale Offshore Wind Turbines Under Earthquakes and Typhoons written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
