Simple method for approximate analysis of framed tube structures

Abstract

Framed tube structures are particularly suitable for tall buildings. They act primarily like cantilevered box beams and since they generally have much larger lateral dimensions than the internal shear wall cores, they are more effective in resisting the overturning moments of the lateral loads. However, due to flexural and shear flexibilities of the frame members, the basic beam bending actions of the framed tubes are complicated by the occurrence of shear lag, which could significantly affect the stress distributions in the frame panels and reduce the lateral stiffness of the structures. In this paper, a simple hand-calculation method is proposed for approximate analysis of framed tube structures with the shear lag effects taken into account. This method is suitable for quick evaluations during the preliminary design stage and can provide a better understanding of the effects of various parameters on the overall structural behavior. Numerical examples are given to demonstrate the case of application and accuracy of the proposed method.