Dynamic analysis of an observation tower subjected to wind loads using ANSYS

Abstract

Engineers today are dedicated towards designing safe and long-lasting structures with better life spans. These characteristics and new innovations have been a huge contribution in the field of Structural Dynamics. This parameter of determination of safety and quality is used in the check list of almost all established organizations today to check, test, and experiment. Present work focuses on assessment of the stability of an observation deck on a tower subjected to wind loads. The tower has been simplified for ease in modelling. The tower is a combination of three concrete columns having the cross section of a hollow tube. The diameters of the columns are different, having the same thickness. At the intersection point of the 2nd and 3rd column is an observation deck. The deck has been idealized as an ellipsoid. The structure is under the influence of wind load acting periodically. It is also mentioned how the effects of winds change with change in height. The following work is divided into three parts in order to conduct the analysis aptly. This involves consideration of two natural frequencies being estimated using Rayleigh's method. A cubic polynomial is used to imitate the deflection pattern of the structure. In later stages, Modal analysis of the structure is performed on ANSYS and lastly, Transient analysis is also conducted by applying wind loads and serviceability of the observation deck is assessed. Results showed that the structure is not safe based on the amount of deformations and accelerations that occur on it.