Deterministic model for wind-induced oscillations of buildings

Abstract

A linearized deterministic model is proposed for the coupled lateral and torsional motions of a tall, slender structure in turbulent atmospheric boundary layer. The resultant force acting on the structure is represented as a vector sum of the aerodynamic excitation forces due to atmospheric turbulent and wake-excitation force due to vortex shedding. The turbulence velocity and the wake-excited across-wind force are modeled by cosinusoidal functions of closely spaced frequencies and random phase angles, using the appropriate power spectra. The proposed analytical model predicts the longitudinal, lateral, and torsional motions of a slender structure using the predetermined lift, drag, and moment coefficients of a given geometric shape. The predicted peak displacement and acceleration responses are found to compare reasonably well with the published experimental results.