Investigating the effect of form curvature on diagrid tall buildings considering wind loads

The use of curved forms in tall buildings has increased recently due to their structural and esthetic advantages. Diagrid structures are typically used for these buildings because of their ability to express curved forms. There are, however, few studies about the curvature of tall buildings. This paper examines the effect of curvature on the wind force on tall curved buildings with diagrid system. So, to achieve this, the form of tall curved buildings is investigated, and the commonly used equations that constitute their form are determined. Then, applying computational fluid dynamics simulation, wind force was calculated on the developed alternatives which were created by the equations. Besides, the structural mass of each model is calculated by optimizing the cross-section of the members. It is concluded that considering the conditions of the applied model, by increasing the concavity of the form, the suction on the building's facade increases. Further, with the increase of the concavity in the plan and elevation, the along wind force on the structure and overturning moment increases. Also, it is observed that the structural efficiency of curvilinear buildings is only appropriate to a certain extent of curvature, and with its increase, the structural efficiency decreases. This article offers useful information for the preliminary design of tall buildings.