MODELING WIND LOADS FOR AERODYNAMIC INSTABILITY OF A CHIMNEY

Abstract

The analysis of chimney oscillations under the influence of the pulsating component of wind load is based on the use of numerical methods, combined with aerodynamic model testing. Wind exposure parameters are commonly modeled using wind tunnel experiments in a uniform flow for a regular regime characterized by a quadratic time dependence of the lift force. This article presents the results of an analytical approach to modeling the pulsating component of wind load in the form of periodic alternating impulses with a quadratic dependence. The resolving equations for the response of the reinforced concrete chimney computational model (RCCM), represented by a discrete dissipative system (DDS), are derived using time-dependent analysis theory. The energy dissipation effect is taken into account using a non-proportional damping model. An analysis of the transverse oscillations of the RCCM under resonant vortex-induced excitation is conducted. Variations in the periodicity of wind pulsations corresponding to the three lowest natural frequencies of the DDS are considered, and the accuracy of the solution of the dynamic problem is evaluated.