رحمت اعظمی

The goal of this study is to examine the vibrations and deformation of tubular towers that support small-scale wind turbines in urban environments. The primary objective is to investigate how steady and turbulent urban winds affect the vibrations, deformation, and dynamic behavior of a wind turbine tower constructed from S355 steel. The tower has specific dimensions: 15 m height, diameter of base 0.6 m, 0.3 m as top diameter, and a wall thickness of 8 mm. This tower is modeled as a shell structure in ABAQUS software, and the boundary conditions are defined so that its base is fixed and its top is free. Also, the equivalent concentrated mass of the nacelle and turbine rotor, 1500 kg, has been considered at the top of the tower. The results showed that the presence of urban turbulent wind, which was simulated with the Kaimal spectral model and a turbulence intensity of 25%, did not have much effect on the natural frequencies, and their changes were less than 2%. The modal characteristics of the structure under turbulent conditions remain nearly constant when compared to steady-state conditions. In the second step, the static and dynamic responses of the tower under two scenarios: steady and urban turbulent wind have been compared. The results showed that the total deformation in the steady state was 92 mm, while in turbulent conditions it increased to 138 mm, resulting in an approximate 50% increase. The maximum Von Mises equivalent stress increases from 138 MPa in the steady state to 204 MPa in the turbulent state