Assessment of translational-torsional coupling in asymmetric uniform wall-frame structures

A method to predict the degree of translational-torsional coupling of mixed-bent-type multistory building structures subject to dynamic loading is presented. The method is based on the treatment of nonproportionate structures as a particular class of regular proportionate ones, and on the generalized representation of asymmetric structures by shear-flexure, torsion-warping cantilevers. The method is applicable to structures consisting of any combination of walls and frames that are uniform over their height. The concept and location of the significant centers of reference, such as the shear centers and the centers of resistance, of mixed-bent-type multistory building structures are clarified, and the significance of the coupled-period ratio for the assessment of the coupling effect is discussed. The derivation of the method, and comparisons of results with those obtained by three-dimensional (3D) finite-element dynamic analyses of discrete member models, are given. A worked example illustrates the application of the method.