Download or read book A General Method for Fatigue Analysis of Vertical Axis Wind Turbine Blades written by Paul S. Veers and published by . This book was released on 1983 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Approach to the Fatigue Analysis of Vertical Axis Wind Turbine Blades written by Paul S. Veers and published by . This book was released on 1981 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Approach to the Fatigue Analysis of Vertical axis Wind turbine Blades written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A cursory analysis of the stress history of wind turbine blades indicates that a single stress level at each wind speed does not adequately describe the blade stress history. A statistical description is required. Blade stress data collected from the DOE/ALCOA Low Cost experimental turbines indicate that the Rayleigh probability density function adequately describes the distribution of vibratory stresses at each wind speed. The Rayleigh probability density function allows the distribution of vibratory stresses to be described by the RMS of the stress vs. time signal. With the RMS stress level described for all wind speeds, the complete stress history of the turbine blades is known. Miner's linear cumulative damage rule is used as a basis for summing the fatigue damage over all operating conditions. An analytical expression is derived to predict blade fatigue life.
Download or read book Review of Wind Simulation Methods for Horizontal axis Wind Turbine Analysis written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report reviews three reports on simulation of winds for use in wind turbine fatigue analysis. The three reports are presumed to represent the state of the art. The Purdue and Sandia methods simulate correlated wind data at two points rotating as on the rotor of a horizontal-axis wind turbine. The PNL method at present simulates only one point, which rotates either as on a horizontal-axis wind turbine blade or as on a vertical-axis wind turbine blade. The spectra of simulated data are presented from the Sandia and PNL models under comparable input conditions, and the energy calculated in the rotational spikes in the spectra by the two models is compared. Although agreement between the two methods is not impressive at this time, improvement of the Sandia and PNL methods is recommended as the best way to advance the state of the art. Physical deficiencies of the models are cited in the report and technical recommendations are made for improvement. The report also reviews two general methods for simulating single-point data, called the harmonic method and the white noise method. The harmonic method, which is the basis of all three specific methods reviewed, is recommended over the white noise method in simulating winds for wind turbine analysis.
Download or read book Testing and Evaluation of a 500 kW Vertical axis Wind Turbine written by M. C. Wehrey and published by . This book was released on 1985 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Data Editing for Blades of Horizontal Axis Wind Turbines written by Pratumnopharat Panu and published by LAP Lambert Academic Publishing. This book was released on 2015-11-12 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: In predicting performance of wind turbines, the blade element momentum (BEM) theory is still commonly used by wind turbine designers and researchers. This book deals with several up-to-date models added to the BEM theory to get more realistic prediction. In evaluating fatigue damage of wind turbine blade, stress-life approach and Miner's linear cumulative damage rule are mentioned. Wind turbine blades are the most critical components of HAWT. Full-scale blade fatigue testing is required to verify that the blades possess the strength and service life specified in the design. Unfortunately, the test must be run for a long time period. This problem led the blade testing laboratories to accelerate fatigue testing time. To achieve the objective, two novel methods called STFT- and WT-based fatigue damage part extracting methods are used to generate the edited stress-time history. Blade testing laboratories can use this history to accelerate fatigue testing time. STFT- and WT-based fatigue damage part extracting methods proposed in this book are suggested as alternative methods in accelerating fatigue testing time, especially for the field of wind turbine engineering.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Download or read book Fatigue Life Prediction of Composites and Composite Structures written by Anastasios P. Vassilopoulos and published by Woodhead Publishing. This book was released on 2019-10-08 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue Life Prediction of Composites and Composite Structures, Second Edition, is a comprehensive review of fatigue damage and fatigue life modeling and prediction methodologies for composites and their use in practice. In this new edition, existing chapters are fully updated, while new chapters are introduced to cover the most recent developments in the field. The use of composites is growing in structural applications in many industries, including aerospace, marine, wind turbine and civil engineering. However, there are uncertainties about their long-term performance, including performance issues relating to cyclic fatigue loading that hinder the adoption of a commonly accepted credible fatigue design methodology for the life prediction of composite engineering structures. With its distinguished editor and international team of contributors, this book is a standard reference for industry professionals and researchers alike. - Examines past, present and future trends associated with the fatigue life prediction of composite materials and structures - Assesses novel computational methods for fatigue life modeling and prediction of composite materials under constant amplitude loading - Covers a wide range of techniques for predicting fatigue, including their theoretical background and practical applications - Addresses new topics and covers contemporary research developments in the field
Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1983 with total page 1028 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Case Studies for Fatigue Education written by Ralph Ivan Stephens and published by ASTM International. This book was released on 1994 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides engineering educators and students with a broad range of non- trivial, real-world fatigue problems/situations and solutions for use in the classroom. The 13 cases involve new designs, rework designs, failure analysis, prototype decisions, environmental aspects, metals, non-metals, components, structures, and fasteners. The cases bring out the need for students to integrate elements of engineering that commonly enter into a fatigue design or failure analysis. No index. Annotation copyright by Book News, Inc., Portland, OR
Download or read book Fatigue Life Prediction for Wind Turbines written by TD. Ashwill and published by . This book was released on 1994 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbines are fatigue-critical machines used to produce electrical energy from the wind. These rotating machines are subjected to combinations of wind, gravity, and gyroscopic loadings that are highly irregular in nature. Historical examples of fatigue problems in both research and commercial wind-turbine development are presented. Some example data on wind-turbine environments, loadings, and material properties are also shown. Before a description of how the authors have chosen to attack the cumulative damage assessment, questions are presented for the reader's reflection. The solution technique used by the authors to define the loading spectrum for wind turbines is then presented. Special emphasis is placed on the development of a loading spectrum for use in the fatigue analysis. Less attention is paid to methods of cumulative damage assessment; Miner's rule and constant amplitude S-n data are used. A case study then applies the procedures to an actual wind-turbine blade joint. The wind turbine is the 34-m diameter vertical axis wind turbine (VAWT) erected by Sandia National Laboratories near Bushland, TX. The case study examines parameter sensitivities for realistic uncertainties in inputs defining the turbine environment, stress response, and material properties. The fatigue lifetimes are calculated using a fatigue analysis program, called LIFE2, which was developed at Sandia.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Fatigue Analysis and Testing of Wind Turbine Blades written by Peter Robert Greaves and published by . This book was released on 2013 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract:This thesis focuses on fatigue analysis and testing of large, multi MW wind turbine blades. The blades are one of the most expensive components of a wind turbine, and their mass has cost implications for the hub, nacelle, tower and foundations of the turbine so it is important that they are not unnecessarily strong. Fatigue is often an important design driver, but fatigue of composites is poorly understood and so large safety factors are often applied to the loads. This has implications for the weight of the blade. Full scale fatigue testing of blades is required by the design standards, and provides manufacturers with confidence that the blade will be able to survive its service life. This testing is usually performed by resonating the blade in the flapwise and edgewise directions separately, but in service these two loads occur at the same time. A fatigue testing method developed at Narec (the National Renewable Energy Centre) in the UK in which the flapwise and edgewise directions are excited simultaneously has been evaluated by comparing the Palmgren-Miner damage sum around the blade cross section after testing with the damage distribution caused by the service life. A method to obtain the resonant test configuration that will result in the optimum mode shapes for the flapwise and edgewise directions was then developed, and simulation software was designed to allow the blade test to be simulated so that realistic comparisons between the damage distributions after different test types could be obtained. During the course of this work the shortcomings with conventional fatigue analysis methods became apparent, and a novel method of fatigue analysis based on multi-continuum theory and the kinetic theory of fracture was developed. This method was benchmarked using physical test data from the OPTIDAT database and was applied to the analysis of a complete blade. A full scale fatigue test method based on this new analysis approach is also discussed.
Download or read book Wind Energy Technical Reading List written by and published by . This book was released on 1988 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Energy Update written by and published by . This book was released on 1984 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1984 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes all works deriving from DOE, other related government-sponsored information and foreign nonnuclear information.
Download or read book Sixth Biennial Wind Energy Conference and Workshop written by and published by . This book was released on 1983 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
