May 12, 2022
Component fatigue of wind turbines made of reinforced concrete and prestressed concrete under high-cycle loading
On May 1, 2022, the new joint research project "WinConFat-Structure: Component fatigue of wind turbines made of reinforced and prestressed concrete under highly cyclic loading" will start under the leadership of the Institute of Solid Construction at the Technical University of Dresden with a duration of three years. It is funded by the German Federal Ministry of Economics and Climate Protection BMWK with a total of 1.7 million euros as part of the German government's 7th energy research program "Innovations for the energy transition". The consortium aims at a general extension and improvement of the verification concepts against fatigue in existing regulations as well as the further development of monitoring concepts and methods for the determination of the real fatigue of wind turbines and thus the more accurate measurement-based determination of remaining service lives of existing turbines. The joint research project thus closes the gap between basic research and practical application.
In the previous joint research project WinConFat (FKZ 0324016), the fatigue behavior of concrete, reinforcing steel and their bond was addressed at the material level. The aim was to enable the improvement of the current design concept by fatigue investigations up to the range of very high load cycles (> 107). In WinConFat, material investigations on normal and high-strength concrete under compressive swell loading were realized on an unprecedented scale. This extensive research work forms the essential basis for further developments of the design concept for concrete fatigue. However, additional analyses on structural components, going beyond pure material investigations, are required by the regulatory bodies, such as the Expert Committee on Wind Power Plants at the German Institute for Structural Engineering (DIBt). These are currently not available, which means that the findings to date cannot yet be transferred to design practice. The three-year project "WinConFat-Structure", which has now been approved, is focusing on the transfer of results from the material level to the component and structure level, which is still outstanding. The following goals are to be achieved:
I. Clarification of the interaction of concrete and reinforcement in fatigue loading of structural members.
II. development of design models to account for fatigue loading in dry joints of precast concrete segments
III. further development of numerical models and engineering models for fatigue analysis of concrete wind turbine towers
IV. Development of methods for in-situ observation of fatigue-induced damage processes in concrete wind turbine towers
V. Summary of results from WinConFat and WinConFat-Structure into a probabilistic based design model for concrete fatigue.
About the project consortium
The consortium consists of the Institute of Solid Construction of the Technical University of Dresden, the Chair and Institute of Solid Construction of the RWTH Aachen, the Institute of Solid Construction of the Leibniz University of Hannover and the Federal Institute for Materials Research and Testing. The project partners contribute many years of experience in the fields of wind energy and fatigue research and are already a well-established consortium due to the very successful cooperation in the previous joint project WinConFat. Professional technical support is provided by the associated partners e.disnatur GmbH, H+P Ingenieuere GmbH, Max Bögl Bauservice GmbH & Co. KG, Nordex SE & Co. KG, TÜV NORD EnSys GmbH & Co. KG and Vallen Systeme GmbH. The utilization of results and transfer into practical aids are supported and accompanied by the German Committee for Reinforced Concrete and the German Concrete and Construction Engineering Association E.V.
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