Wind turbines, both single and arrayed, are installed in areas located onshore, near-shore, offshore and in urban areas where they are integrated with buildings. Onshore and offshore wind power industry is growing fast (Oh et al., 2013; Barthelmie et al. 2009; Lozano-Minguez et al., 2011; Hameed et al., 2011). Due to their enormous size and due to the fact that wind turbines may be subjected to extreme wind conditions during their lifetime, it is imperative that proper assessment of wind load should be carried. Verheij (1988) had developed a Gust Model for the design of large wind turbines and explained the various wind loads and their causes. Saranyasoontorn et al. (2004) investigated the influence of turbulence conditions on the design loads
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Early offshore wind development is expected to be in shallow water, which raises interest about the design of the turbine’s foundation system. The cost of offshore foundations for these developments is a significant portion of their overall installation cost, about 35% (Byrne and Houlsby, 2003), making the development of suitable designs for the foundations an essential task. The engineering expertise in the design and construction of marine structures came mainly from platforms serving in the oil industry. However, there is a major difference between the platforms and wind turbines in terms of vertical to horizontal load ratios, which impose different demands on the their foundation designs. The literature has relatively minimal guidance for the evaluation of wind-induced loads that can be used for the design of offshore and onshore wind turbines’ foundation …show more content…
This information is used to characterize the force and moment exerted by the turbine at the top of the foundation column. Also, IEC (2009) specifies additional requirements for assessment of the external conditions at an offshore wind turbine site and specifies essential design requirements to ensure the engineering integrity of offshore wind turbines. Svensson (2010) used typical wind loads for onshore wind turbines situated on the west coast of Sweden, for the design aspects of different types of foundations. The actual loads acting on the foundation (provided by the manufacturer) were given in form of two forces, one horizontal and one vertical, one bending moment and one twisting moment. Both manual calculations and numerical analyses were performed for the design procedure of a case study of an 80 m high wind turbine with actual loads. In a report published by the National Renewable Energy Laboratory (NREL), all load data were presented for a 5 MW NREL reference wind turbine (Jonkman et al., 2009). The report includes rotor thrust and torque for different wind speeds. These loads were obtained numerically by the FAST (Fatigue, Aerodynamics, Structures, and Turbulence) program (Buhl Jr and Manjock, 2006). Ragan and Manuel (2007) presented statistical extrapolation methods for estimating
Early offshore wind development is expected to be in shallow water, which raises interest about the design of the turbine’s foundation system. The cost of offshore foundations for these developments is a significant portion of their overall installation cost, about 35% (Byrne and Houlsby, 2003), making the development of suitable designs for the foundations an essential task. The engineering expertise in the design and construction of marine structures came mainly from platforms serving in the oil industry. However, there is a major difference between the platforms and wind turbines in terms of vertical to horizontal load ratios, which impose different demands on the their foundation designs. The literature has relatively minimal guidance for the evaluation of wind-induced loads that can be used for the design of offshore and onshore wind turbines’ foundation …show more content…
This information is used to characterize the force and moment exerted by the turbine at the top of the foundation column. Also, IEC (2009) specifies additional requirements for assessment of the external conditions at an offshore wind turbine site and specifies essential design requirements to ensure the engineering integrity of offshore wind turbines. Svensson (2010) used typical wind loads for onshore wind turbines situated on the west coast of Sweden, for the design aspects of different types of foundations. The actual loads acting on the foundation (provided by the manufacturer) were given in form of two forces, one horizontal and one vertical, one bending moment and one twisting moment. Both manual calculations and numerical analyses were performed for the design procedure of a case study of an 80 m high wind turbine with actual loads. In a report published by the National Renewable Energy Laboratory (NREL), all load data were presented for a 5 MW NREL reference wind turbine (Jonkman et al., 2009). The report includes rotor thrust and torque for different wind speeds. These loads were obtained numerically by the FAST (Fatigue, Aerodynamics, Structures, and Turbulence) program (Buhl Jr and Manjock, 2006). Ragan and Manuel (2007) presented statistical extrapolation methods for estimating