Download or read book An Asssessment of Surface Ice Sheet Loads and Their Effects on an Offshore Wind Turbine Structure written by Eric M. Wells and published by . This book was released on 2012 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines the effects of surface ice sheets on an offshore wind turbine. First, the main ice load cases are presented, and methods used to calculate the loads from each of these cases are explained. These load cases consist of loads from moving ice sheets, loads from non-moving ice sheets, and loads from agglomerated masses of ice, called ice ridges. Next, the data required to conduct the load calculations are presented from sources applicable to an offshore site in Lake Erie, which is the location of interest in this work. The load calculation methods were implemented into a wind turbine simulation software package, and simulations were run subjecting an offshore wind turbine to extreme ice loads combined with a large representative wind load. Results from these simulations are presented, which show the relative magnitude of the effects of the ice loads compared to the magnitude of the effects of the wind load. It was found that the effects on the foundation due to extreme ice loads can be much larger than the effects caused by a large representative wind load. Also presented in this work is an examination of how the ice loads would influence the design of an offshore wind turbine foundation (i.e. how much bigger should the foundation be to support the ice loads). The simulation results presented in this study indicate that the surface ice sheet loads can be much larger than the wind loads and could be the driving parameter of the design of offshore wind turbine foundations in areas where ice can occur.

Download or read book Ice Load Project Final Technical Report written by and published by . This book was released on 2014 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: As interest and investment in offshore wind projects increase worldwide, some turbines will be installed in locations where ice of significant thickness forms on the water surface. This ice moves under the driving forces of wind, current, and thermal effects and may result in substantial forces on bottom-fixed support structures. The North and Baltic Seas in Europe have begun to see significant wind energy development and the Great Lakes of the United States and Canada may host wind energy development in the near future. Design of the support structures for these projects is best performed through the use of an integrated tool that can calculate the cumulative effects of forces due to turbine operations, wind, waves, and floating ice. The dynamic nature of ice forces requires that these forces be included in the design simulations, rather than added as static forces to simulation results. The International Electrotechnical Commission (IEC) standard[2] for offshore wind turbine design and the International Organization for Standardization (ISO) standard[3] for offshore structures provide requirements and algorithms for the calculation of forces induced by surface ice; however, currently none of the major wind turbine dynamic simulation codes provides the ability to model ice loads. The scope of work of the project described in this report includes the development of a suite of subroutines, collectively named IceFloe, that meet the requirements of the IEC and ISO standards and couples with four of the major wind turbine dynamic simulation codes. The mechanisms by which ice forces impinge on offshore structures generally include the forces required for crushing of the ice against vertical-sided structures and the forces required to fracture the ice as it rides up on conical-sided structures. Within these two broad categories, the dynamic character of the forces with respect to time is also dependent on other factors such as the velocity and thickness of the moving ice and the response of the structure. In some cases, the dynamic effects are random and in other cases they are deterministic, such as the effect of structural resonance and coupling of the ice forces with the defection of the support structure. The initial versions of the IceFloe routines incorporate modules that address these varied force and dynamic phenomena with seven alternative algorithms that can be specified by the user. The IceFloe routines have been linked and tested with four major wind turbine aeroelastic simulation codes: FAST, a tool developed under the management of the National Renewable Energy Laboratory (NREL) and available free of charge from its web site; Bladed[4], a widely-used commercial package available from DNV GL; ADAMS[5], a general purpose multi-body simulation code used in the wind industry and available from MSC Software; and HAWC2[6], a code developed by and available for purchase from Danmarks Tekniske Universitet (DTU). Interface routines have been developed and tested with full wind turbine simulations for each of these codes and the source code and example inputs and outputs are available from the NREL website.

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.

Download or read book Bottom Fixed Platform Dynamics Models Assessing Surface Ice Interactions for Transitional Depth Structures in the Great Lakes written by and published by . This book was released on 2015 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: To create long-term solutions for offshore wind turbines in a variety of environmental conditions, CAE tools are needed to model the design-driving loads that interact with an offshore wind turbine system during operation. This report describes our efforts in augmenting existing CAE tools used for offshore wind turbine analysis with a new module that can provide simulation capabilities for ice loading on the system. This augmentation was accomplished by creating an ice-loading module coupled to FAST8, the CAE tool maintained by the NREL for simulating land-based and offshore wind turbine dynamics. The new module includes both static and dynamic ice loading that can be applied during a dynamic simulation of the response of an offshore wind turbine. The ice forces can be prescribed, or influenced by the structure's compliant response, or by the dynamics of both the structure and the ice floe. The new module covers ice failure modes of spalling, buckling, crushing, splitting, and bending. The supporting structure of wind turbines can be modeled as a vertical or sloping form at the waterline. The Inward Battered Guide Structure (IBGS) foundation designed by Keystone Engineering for the Great Lakes was used to study the ice models coupled to FAST8. The IBGS foundation ice loading simulations in FAST8 were compared to the baseline simulation case without ice loading. The ice conditions reflecting those from Lake Huron at Port Huron and Lake Michigan at North Manitou were studied under near rated wind speed of 12 m/s for the NREL 5-MW reference turbine. Simulations were performed on ice loading models 1 through 4 and ice model 6 with their respective sub-models. The purpose of ice model 5 is to investigate ice loading on sloping structures such as ice-cones on a monopile and is not suitable for multi-membered jacketed structures like the IBGS foundation. The key response parameters from the simulations, shear forces and moments from the tower base and IBGS foundation base, were compared. Ice models 1 and 6 do not significantly affect the tower fore-aft shear and moment. However, ice model 2 (dynamic analyses), model 3 (random ice loading), and model 4 (multiple ice failure zone loading) show increased effect on the tower fore-aft shear and moment with significant effect from ice model 3.1. In general ice loading creates large reaction forces and moments at the base of the IBGS foundation; the largest occurred in model 1.1 (steady creep ice indentation loading) followed by model 3.1 (random creep ice indentation loading). In general the power production from the ice loading cases had little deviation from the baseline case without ice loading. For ultimate limit state (ULS), ice model 1.1 ice and 3.1 appear to be the ice most critical models to consider at an early stage of design. Ice model 4 is an important tool for assessing structural fatigue.

Download or read book Multiphysics of Wind Turbines in Extreme Loading Conditions written by Arash Soleiman Fallah and published by Academic Press. This book was released on 2024-01-26 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphysics of Wind Turbines in Extreme Loading Conditions addresses the extreme transient loading of wind turbines through a multiphysics modeling approach, notably by considering the dynamic effects and the nonlinearities of the physics involved in such situations. The book forms the basis for understanding multiphysic numerical simulations conducted on onshore and offshore wind turbines and subjected to extreme loading conditions, including storms, earthquakes, blasts, impacts, and tsunamis. The multiphysics approaches used in this book are explained in each chapter, with algorithms then turned into numerical codes to attain a realistic picture of the dynamic response in each scenario. With numerical methods and loading data explained, the complexity of potential problems encountered when extreme dynamic loads are discussed, along with loading types and their effects. The book fills a specific niche in wind power, namely extreme transient loading of wind turbine, offering information and industrial practices as wind energy makes it useful to practice engineers, designers, undergraduate and graduate students. Defines best practices for unique scenarios which are not readily available in the wider literature, such as extreme load conditions, earthquake and storm scenarios Includes multi-physics methods and specific applications within the demands of extreme conditions Offers numerical simulations of both onshore and offshore wind turbines in one place

Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-11 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Ice as a Load supporting Surface written by Kenneth A. Linell and published by . This book was released on 1958 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ice in the mass is perhaps best described as a highly viscous material having the characteristics of a solid. It may fracture like a brittle material, or it may flow and deform gradually depending upon the intensity of the stress and rate of loading, the temperature, the degree of confinement and the structure of the ice itself. The proportional limit of the stress-strain curve for ice has been reported to be on the order of 20 to 25 psi or even less. At higher static load intensities ice will deform at a steady rate; the higher the stress, the higher the rate. Since floating ice is normally stressed to far beyond the proportional limit in order to carry useful loads, theoretical stress analysis methods using the theory of elasticity become no longer strictly applicable and must be applied with caution. Fortunately most load applications of appreciable magnitude on floating ice involve periods of stress duration much shorter than the structural designer deals with in the case of permanent structures, such as buildings and bridges, and the plastic deformation is usually not as serious a matter as it might seem.

Download or read book Offshore Energy Structures written by Madjid Karimirad and published by Springer. This book was released on 2014-12-05 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides all the key information needed to design offshore structures for renewable energy applications successfully. Suitable for practicing engineers and students, the author conveys design principles and best practices in a clear, concise manner, focusing on underlying physics while eschewing complicated mathematical detail. The text connects underlying scientific theory with industry standards and practical implementation issues for offshore wind turbines, wave energy converters and current turbines. Combined concepts such as wave-wind energy platforms are discussed, as well. Coverage of design codes and numerical tools ensures the usefulness of this resource for all those studying and working in the rapidly expanding field of offshore renewable energy.

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:

Download or read book Ships and Offshore Structures XIX written by Carlos Guedes Soares and published by CRC Press. This book was released on 2015-09-03 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: This three-volume work presents the proceedings from the 19th International Ship and Offshore Structures Congress held in Cascais, Portugal on 7th to 10th September 2015. The International Ship and Offshore Structures Congress (ISSC) is a forum for the exchange of information by experts undertaking and applying marine structural research.The aim of

Download or read book Ice Forces on Flat Vertical Indentors Pushed Through Floating Ice Sheets written by Naoki Nakazawa and published by . This book was released on 1990 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structures placed in an ice environment should be able to withstand the ice forces that are produced by the motion of a floating ice sheet. To observe the crushing failure of ice and to characterize the magnitude and nature of ice forces, an experimental study was conducted by pushing vertical, flat indentors through floating ice sheets made up of freshwater, columnar ice. Depending on the velocity of the indentor, ductile or brittle behavior of ice was observed. Microcracks and macrocracks were observed during the tests. The energy used to produce the maximum ice force was found to be approximately the same for different indentor velocities. The positions of the resultant forces were found to be in the center of the contact area. The area of the ice damaged by the first peak loading of the identor was about the same, even when the indentor velocities were different. Acoustic emission signals were measured during indentation experiments, and these were found to correlate with the ice force that produces strain and microcracking in the ice. Keywords: Ice mechanics; Cracking/fracturing; Coastal engineering; Offshore structures; Load distribution; Crushing; Effective pressure; Freshwater ice; Ice forces; Laboratory tests; Macrocracking; Microcracking. (EDC).

Download or read book Ice Mechanics and Risks to Offshore Structures written by T. Sanderson and published by Springer. This book was released on 1988-05-31 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: ' This is a book for which Arctic ice engineers and scientists have been waiting for years. It is the first reference text to deal in a comprehensive way with ice loads on marine structures. It is also written in a clear and attractive style and it is a pleasure to read. ' Polar Record

Download or read book Ice Interaction with Offshore Structures written by A. B. Cammaert and published by Van Nostrand Reinhold Company. This book was released on 1988 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Economics of Wind Energy written by and published by EWEA. This book was released on 2009 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fossil Energy Update written by and published by . This book was released on 1986 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Engineering Index Annual written by and published by . This book was released on 1992 with total page 2264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its creation in 1884, Engineering Index has covered virtually every major engineering innovation from around the world. It serves as the historical record of virtually every major engineering innovation of the 20th century. Recent content is a vital resource for current awareness, new production information, technological forecasting and competitive intelligence. The world?s most comprehensive interdisciplinary engineering database, Engineering Index contains over 10.7 million records. Each year, over 500,000 new abstracts are added from over 5,000 scholarly journals, trade magazines, and conference proceedings. Coverage spans over 175 engineering disciplines from over 80 countries. Updated weekly.

Download or read book Offshore Structures written by Günther Clauss and published by Springer. This book was released on 2014-09-25 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: This updated translation from the original German edition provides general background information on oceanology and ocean engineering is given, along with descriptions of drilling techniques, offshore structures and hydrocarbon production at sea. The main part of the book is concerned with the hydrostatic and hydrodynamic analysis of marine structures, followed by an evaluation of marine structure reliability. Environmental conditions affecting marine structures, wave statistics, and the application of reliability theory to code development are also discussed. Students and practising engineers who have an interest in the analysis of marine structures will find this book an invaluable reference.