Performance based Design of a tall building having elliptic plan shape against the wind

Population growth, space limitation, economic and social factors are some of the reasons that led to the construction of tall buildings. However, the invention of light weight and durable materials has made tall buildings with low damping and high vibration period and sensitive to wind forces. Therefore, the study and analysis of tall buildings under wind forces seem necessary. The purpose of the present research work is to provide the necessary solutions for performance based design of a tall building having elliptic plan shape against the wind. In the present study, a tall elliptical building is exposed to wind interaction. Moreover, wind modeling and building specifications are performed in ANSYS.17 software. To simulate the atmospheric boundary layer in the software as a virtual wind tunnel, two parameters of the mean wind speed and turbulence includes length and intensity, are required. The results of software analysis were presented as a time history of longitudinal and transverse acceleration at three different heights of the building for four various mean wind speeds in short afterbody orientation for perpendicular to wind direction and 72 m/s in wind direction, then the standard deviation of acceleration was calculated and placed in standard curves of the regulation and interpreted. The effect of different factors on the performance of tall buildings against the wind is a type of response (alongwind or acrosswind), mean wind speed, orientation of the building, and the height of the desired point from the ground. Results show that the acrosswind response of tall buildings to wind does not follow a specific law and is a function of the mean wind speed, height of the building, and the alongwind and acrosswind response of the building ,i.e, displacement and accelerations .