Inhomogeneous beam-like models for the dynamic analysis of multistorey buildings

The present paper proposes a simplified inhomogeneous beam-like model, suitable for the dy-namic analysis of buildings with non-uniform vertical distribution of mass and stiffness. Asymmetric distribu-tion of stiffness within the floors, which leads to torsional effects, can be also taken into account. The equa-tions of motion of the proposed spatial asymmetric beam-like model are derived through the application of Hamilton’s principle. The linear dynamic behaviour of the inhomogeneous beam-like element is then eva-luated by discretizing the continuous model according to a Rayleigh-Ritz approach based on a suitable num-ber of modal shapes of uniform shear torsional beam. The comparison of the results with those obtained by means of three-dimensional FEM models shows the efficacy of the proposed approach.