Parametric Study of the Crosswind Response of Tall Buildings Using Frequency Domain Analysis and Random Vibration Method

Abstract

By increasing the height and slenderness of tall buildings, the wind-induced dynamic response especially crosswind response becomes the governing parameter in the occupant comfort requirement of tall buildings. In the present study, crosswind response of tall buildings has been investigated using the frequency domain analysis of multi-degrees-of-freedom systems based on the random vibration method. The tall structure has been modeled as a vertical cantilever beam with the masses lumped at the nodes. All the modeling and analysis procedure, including element meshing, determining the transfer matrix, calculating the matrix of crosswind force spectrum, and the numerical integration to obtain the root-mean-square (RMS) displacement and acceleration responses are carried out using MATLAB software. The effect of different parameters, such as basic wind speed, aspect ratio, side ratio for rectangle section and top to bottom width ratio for tapered tall buildings has been investigated. The results show that the slenderness ratio has an important role on the across-wind response. For tapered buildings, the crosswind displacement response decreases considerably with increasing the top to bottom width ratio. For the studied tall buildings, the crosswind acceleration response is higher than the occupant comfort level and it requires to be reduced using an appropriate control strategy.

Keywords

• crosswind response
• tall building
• frequency domain analysis
• random vibration
• parametric study