Analysis and Optimisation of Wind-Induced Vibration Control for High-Rise Chimney Structures

Abstract

Wind is a key factor when determining the safety of high-rise structures, such as buildings, chimneys, or towers. Using dampers to control wind-induced vibration is a safe, effective, and economical method for high-rise structures to employ. In this paper, viscoelastic dampers (VEDs) were used to reduce the dynamic responses of a 75-metre-high chimney. First, a simulation method for the stochastic wind field, based on the modified Fourier spectrum, was proposed. The method provided the accurate data of the wind velocity time history, which then simulated wind pressure through the use of a numerical wind tunnel. Then, the finite element model for the Madagascar chimney structure was built, and a wind-induced vibration analysis of the structure with and without VEDs was carried out under the simulated wind excitation. The optimisation – method, based on the genetic algorithm, was used to optimise the location of the VEDs. It was concluded that the accuracy of the modified Fourier spectrum method (MFSM) was greatly improved, when compared to the spectrum representation method of simulating the stochastic wind field. VEDs can effectively reduce the dynamic responses of chimney towers, especially for the displacement responses. In addition, the proposed optimisation method quickly determined the optimum positions and necessary quantities of VEDs to use, which yielded effective vibration mitigation.