Response and reliability analysis of concrete chimneys under random vortex shedding

Vortex-induced forces on chimneys can be modelled as a random process described by a power spectral density function and a cross-power density function. The response of the chimney to such forces, including aeroelastic interaction, is of significant interest to researchers. In this paper, response and reliability analyses of chimneys under random vortex-induced excitation are presented, in which aeroelastic interaction was duly considered. Both modal and direct spectral analyses are presented, using discrete modelling of a chimney. The reliability of the chimney against vortex-induced forces was determined using Vanmarcke's double barrier crossing analysis. The effects of important parameters such as the turbulence intensity, lift coefficient, correlation length, Strouhal number and total damping on the responses and reliability estimates of three chimneys are investigated. The responses of the chimneys obtained by international wind codes are compared with those determined from random vibration analysis and reasons for the differences in the responses are provided. The novelty of this work is response and reliability analyses of chimneys, including aeroelastic interaction, under random vortex shedding forces using a discrete formulation, and study of the effects of important parameters on chimney responses.