Aeroelastic Model Investigation and Spectral Analysis of a Tall Lattice Tower

Abstract

The aerodynamic responses of a tall steel lattice transmission tower are examined using a 1:100 full aeroelastic model in a boundary-layer flow with adequate turbulence intensities. Since the structure modelled is composed of 583 thin wall steel tubes, it is difficult to construct a perfect aeroelastic model. In this study, an equivalent scattered stiffness method was developed to overcome the difficulties. The results presented and discussed include the aerodynamic force coefficients, acceleration responses and wind load factors at various wind velocities and wind attack angles. It is revealed that the wind load factors increase with wind mean velocity and along the model height. The wind-induced dynamic responses in two sway directions are approximately equal for any wind attack angle. In other words, across-wind vibration is evident. Spectral analysis based on the Kaimal spectrum and F.E.M., which takes into account wind-structure coupling effects, was also developed for calculating the wind-induced dynamic responses. The numerical results of along-wind responses show good agreement with the experimental results.