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 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 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 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 1982 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Energy Research Abstracts written by and published by . This book was released on 1986 with total page 1442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Advances in Artificial Intelligence Software and Systems Engineering written by Tareq Ahram and published by Springer Nature. This book was released on 2020-07-03 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses emerging issues concerning the integration of artificial intelligence systems in our daily lives. It focuses on the cognitive, visual, social and analytical aspects of computing and intelligent technologies, and highlights ways to improve the acceptance, effectiveness, and efficiency of said technologies. Topics such as responsibility, integration and training are discussed throughout. The book also reports on the latest advances in systems engineering, with a focus on societal challenges and next-generation systems and applications for meeting them. Based on the AHFE 2020 Virtual Conference on Software and Systems Engineering, and the AHFE 2020 Virtual Conference on Artificial Intelligence and Social Computing, held on July 16–20, 2020, it provides readers with extensive information on current research and future challenges in these fields, together with practical insights into the development of innovative services for various purposes.
Download or read book Solar Energy Update written by and published by . This book was released on 1982-03 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Stress Analysis of Vertical axis Wind Turbine Blades written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Conference on Sustainable Environment Agriculture and Tourism ICOSEAT 2022 written by Arifin Dwi Saputro and published by Springer Nature. This book was released on 2023-02-10 with total page 1023 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an open access book. ICOSEAT 2022 was held on July 21–23, 2022 in Bangka Island, one of the wonderful places of Indonesia. Articles in the field of Agroindustry and Appropriate Technology 4.0; Environmental and Mining Engineering; Sustainable Development and Tourism Management; Agriculture and Food Engineering; and Marine, Aquaculture and Biological Science. ICOSEAT provides a forum for Academic, Business and Government to present and discuss topics on recent development in those fields.
Download or read book NASA SP written by and published by . This book was released on 1983 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wind Turbine Airfoils and Blades written by Jin Chen and published by Walter de Gruyter GmbH & Co KG. This book was released on 2017-12-04 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind Turbine Airfoils and Blades introduces new ideas in the design of wind turbine airfoils and blades based on functional integral theory and the finite element method, accompanied by results from wind tunnel testing. The authors also discuss the optimization of wind turbine blades as well as results from aerodynamic analysis. This book is suitable for researchers and engineers in aeronautics and can be used as a textbook for graduate students.
Download or read book Static and Fatigue Analysis of Wind Turbine Blades Subject to Cold Weather Conditions Using Finite Element Analysis written by Patricio Lillo and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Canada has aggressive targets for introducing wind energy across the country, but also faces challenges in achieving these goals due to the harsh Canadian climate. One issue which has received little attention in other countries not experiencing these extremes is the behaviour of composite blades in winter conditions. The scope of the work presented is to analyze the static stresses and fatigue response in cold climates using finite element models of the blade. The work opens with a quantification of the extremes of cold experienced in candidate Canadian wind turbine deployment locations. The thesis then narrows its focus to a consideration of the stresses in the root of the composite blades, specifically two common blade-hub connection methods: embedded root carrots and T-bolts. Finite element models of the root are proposed to properly simulate boundary conditions, applied loading and thermal stresses for a 1.5MW wind turbine. It is shown that the blade root is strongly affected by the thermal stresses caused by the mismatch and orthotrophy of the coefficients of thermal expansion of the blade root constituents. Fatigue analysis of a blade is then presented using temperature dependent material properties including estimated fatigue coefficients. It was found that the natural frequencies of a 1.5MW wind turbine blade are not significantly altered at cold temperatures. Additionally, cold temperatures slightly increase stresses in the composite blade skin when the blade is loaded, due to an increase in stiffness. Cold temperatures also lead to higher cyclic flapwise bending moments acting on the blade. However, this increase was found not to affect the lifetime fatigue damage. Finally, it was found that the cold climate as seen in Canada improves the fatigue strength of the saturated composite materials used in the blade. The predicted fatigue damage of the triaxial fabric and the spar cap layers in cold climates was therefore predicted to be half that of the fatigue damage at room temperature. This is caused solely by the temperature dependence of the fatigue coefficient b which requires further experimental verification to validate the numerical results of the current study.
Download or read book Vibrational Analysis of Vertical Axis Wind Turbine Blades written by Onur Kapucu and published by . This book was released on 2014 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:
