PSI - Issue 48

Muhammad Rizky Arga Wijaya et al. / Procedia Structural Integrity 48 (2023) 41–49 Wijaya et al. / Structural Integrity Procedia 00 (2023) 000–000

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1. Introduction Energy is primarily considered the primary driver of industrial, commercial, and residential development worldwide (Adiputra and Utsunomiya, 2019; 2021; Prabowo and Prabowoputra, 2020; Prabowoputra et al., 2020a,b; Tjahjana et al., 2021;Wicaksono et al., 2021; Arifin et al., 2022; Prabowoputra and Prabowo,2020;2022; Prasetyo et al., 2023). To meet the growing energy demand, there are several means and methods, some of which may pollute the environment (Patil et al., 2023). Global warming and air pollution in urban areas are the impacts of using fossil fuel energy. Public awareness of the environment has increased to seek carbon-based fuel alternatives to protect natural resources and reduce CO2 emissions (Widiastuti, 2016). The scarcity of on-renewable natural resources such as petroleum, coal, and natural gas has also become a significant problem for the world. Wind power is gaining attention as a new energy source in overcoming the ecological issues of burning fossil fuels. Wind energy is the most prominent renewable energy source and is the solution to the global energy problem in the future. In the wind turbine system, blades are required to preserve an optimum cross-section for aerodynamics. The blades on the rotor harvest the energy in the wind stream by transmitting rotational energy to the generator as kinetic energy, where the generated electricity can be connected directly to the load or fed to the utility grid. The weight and cost of the turbine are critical for making wind energy competitive with other power sources because research programs have significantly improved the rotor's efficiency and maximized the machine's energy capture. Thus, the real opportunity today is through better, low-cost materials and high-volume production while maintaining reliability. The wind turbine blades' performance depends on the blade's material, the blade's shape, and the blade's angle. In general, the material of the blade should possess high stiffness, low density, and extended fatigue life features. A wide range of materials is used in wind turbines. In recent years, the components of turbines are changing as technology improves and evolves. New component developments are underway now that will significantly change the materials usage patterns. Generally, it is a trend toward lighter-weight and low-cost materials. (Kalagi et al., 2018). This article focuses on assisting the work of designing new wind turbine blades by providing a comparative study of various materials, describing the advantages and disadvantages of all types of materials, reviewing the processing criteria, and knowing the mechanical properties, especially static compression and fatigue properties of the material system. 2. Wind turbine: systems in brief A comprehensive look at blade design has shown that an efficient blade shape is defined by aerodynamic calculations based on chosen parameters and the performance of the selected airfoils. The optimum efficient shape is complex, consisting of aerofoil sections of increasing width, thickness, and twist angle towards the hub. This general shape is constrained by physical laws and is unlikely to change. There is a trade-off to be made between aerodynamic efficiency and structural efficiency: even if a thin blade can be made solid and stiff enough by using lots of reinforcement inside, it might still be better to make the blade a bit thicker (hence less aerodynamically efficient) if it saves so much cost of material that the overall cost of electricity is reduced. Therefore, there is inevitably some iteration in the design process to find the optimum thickness for the blade, as shown in Figure 1.

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Fig. 1. Illustration of wind turbine airfoil: (a) airfoil contours; and (b) airfoil chord line.