Microcomputer analysis of torsionally coupled multistorey buildings-I. Shear beam model

A simplified analysis of torsionally coupled multistorey buildings, suitable for use with microcomputers, is presented in this paper. Interaction between the lateral and torsional components of the response is automatically included in the analysis. Floors are assumed to be rigid diaphragms each with three degrees of freedom. Potential and kinetic energies of the building are calculated and the equations of motion are derived using Lagrange's equations. Interaction in the vertical direction is limited to a floor above and a floor below, as befits a shear beam model. Thus the model is close-coupled. A numerical example and a discussion on the use of the equations of motion are given. The analysis technique presented may be used purely for static response or the calculation of natural frequencies and associated modes of vibration, or finally, for a full time history analysis should deterministic forcing be known or available.