Optimum design of multistory uniform structures with simple eccentricity

A simple formula is presented to predict the conditions under which the degree of translational–torsional coupling of mixed-bent-type multistory eccentric buildings is insignificant and can be neglected in the structural design of such buildings. The formula is applicable to monosymmetric structures consisting of walls and rigid frames that are uniform over the height of the building. The derivation of the formula is based on the technique of representing discrete-member structural models with an equivalent continuum medium and on the findings of an earlier paper presented by the writer, that in eccentric mixed-bent-type structures, under certain circumstances, the eccentricity of the wall system opposes the eccentricity of the frame system and that results in an effectively uncoupled building structure. The accuracy of the formula is examined by means of a parametric study that includes common types of wall-frame monosymmetric structures and comparisons are made with the results obtained by three-dimensional finite element dynamic analyses of discrete member models. Copyright © 2007 John Wiley & Sons, Ltd.