Calculation of the damping of chimneys
van Koten H.
CICIND REPORT Vol. 17, No. 1, 2001
Order No: CR-214
The damping of chimneys is made up from material damping, aerodynamic damping, dissipation of energy in the foundation and damping due to shocks caused by moving masses (as used in dampers). Material damping is one of the most important because it acts continuously. The movements of chimneys in the crosswind direction can become large because the loading can act at the resonant frequency. The acceleration force and the stiffness force are in equilibrium. The resistance against this fluctuating load is caused by the damping only.
This paper presents a method for calculating material damping as a first step to determining the damping required for a linear calculation of chimney response. It also enables the designer to test the effect on damping of varying the parameters of the design.