A Novel Generalized Sandwich Beam for Global Stability Analysis of Tall Buildings with Shear Walls Using a Modified Transfer Matrix Method

Abstract

This research presents the study of the global buckling analysis of tall buildings with shear walls of significant length, where it is not possible to neglect the stiffness due to local shear. In order to correctly idealize the tall building, this research proposes a novel generalized sandwich beam replacement resulting from the generalization of the classical sandwich beam by including an additional mechanism due to the consideration of the local shear stiffness. The association of mechanisms of model shows that the proposed beam results from the series coupling of the classic sandwich beam and the local shear beam. Four characteristic stiffnesses and three kinematic fields associated with the model are considered. The differential equations and boundary conditions governing equilibrium are obtained by applying a variational approach using Hamilton’s principle to the relevant Lagrangian function. A modified transfer matrix method is proposed that diagonalizes the inverse of the zero transfer matrix and reduces the computational cost to solve the equilibrium equations numerically. The modified transfer matrix method allows the analysis to be generalized to buildings with uniform and non-uniform properties along their height considering a constant or variable compressive load along the height of the building. A parametric analysis is presented to evaluate the importance of the inclusion of the local shear mechanism of the shear walls. The results of the numerical examples are encouraging and show that at a reduced computational cost, the presented numerical procedure can greatly help engineers in the preliminary and final structural analysis of tall buildings.