| 1. |
- Mathern, Alexandre, 1986, et al.
(författare)
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Concrete Support Structures for Offshore Wind Turbines: Current Status, Challenges, and Future Trends
- 2021
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 14:7
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Forskningsöversikt (refereegranskat)abstract
- Today’s offshore wind turbine support structures market is largely dominated by steel structures, since steel monopiles account for the vast majority of installations in the last decade and new types of multi-leg steel structures have been developed in recent years. However, as wind turbines become bigger, and potential sites for offshore wind farms are located in ever deeper waters and ever further from the shore, the conditions for the design, transport, and installation of support structures are changing. In light of these facts, this paper identifies and categorizes the challenges and future trends related to the use of concrete for support structures of future offshore wind projects. To do so, recent advances and technologies still under development for both bottom-fixed and floating concrete support structures have been reviewed. It was found that these new developments meet the challenges associated with the use of concrete support structures, as they will allow the production costs to be lowered and transport and installation to be facilitated. New technologies for concrete support structures used at medium and great water depths are also being developed and are expected to become more common in future offshore wind installations. Therefore, the new developments identified in this paper show the likelihood of an increase in the use of concrete support structures in future offshore wind farms. These developments also indicate that the complexity of future support structures will increase due to the development of hybrid structures combining steel and concrete. These evolutions call for new knowledge and technical know-how in order to allow reliable structures to be built and risk-free offshore installation to be executed.
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| 2. |
- Stümpel, Marina, et al.
(författare)
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Experimental investigations on a novel concrete truss structure with cast iron nodes
- 2021
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Ingår i: Engineering Structures. - : Elsevier BV. - 1873-7323 .- 0141-0296. ; 232
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Tidskriftsartikel (refereegranskat)abstract
- Truss structures are among the most efficient load-bearing structures in the building industry. Thus, concrete truss structures were already built in the early years of reinforced concrete construction. However, the difficulties associated with their execution prevented the permanent establishment of concrete truss structures. In this context, this article shows a possibility to further exploit the potential of concrete truss structures. A truss structure consisting of concrete struts and cast iron nodes is presented. The components are connected by a grout, whose bond to the cast iron nodes is ensured by shear keys at the inner surface of the nodes. In order to investigate the load-bearing behaviour of this new connection, an experimental program with two types of tests was conducted: tests on grout-cast iron plate assemblies under axial loading and tests on concrete-cast iron pipes assemblies under bending. The evaluation of these test series and the discussion of the results are the focus of this article. As relevant characteristics of the load-bearing behaviour of the connection the bond strength and stiffness were determined. Different failure modes were observed and need to be addressed for the structural design of the connection. All in all, this study indicates that the new type of connection has a good load-bearing behaviour and could encourage the use of concrete truss structures for future applications.
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