Slenderness Effects in Buildings

Methods for analyzing slenderness effects in tier buildings are proposed. Some of these methods apply to buildings with braced frames, as well as to those with unbraced (space) frames. The simplest methods cover the analysis of buckling and interaction of vertical and lateral forces in a single story under the assumption that the story stiffness is a constant. Next, assuming equal joint rotations in each floor, step-by-step and iteration methods are introduced. Further refinements include consideration of unequal joint rotations and individual-column buckling. The methods are extended to cover torsion in three-dimensional structures and to nonlinear behavior. It is contended that the usual individual-column treatment of slenderness effects is inadequate for most practical cases and in few buildings can sway be regarded as truly inhibited.