Cyclone wind response mitigation of transmission towers by SMA dampers

Abstract

The present study focuses on a means of improving the performance of transmission towers under high-intensity winds in the form of cyclonic winds through the use of shape memory alloy (SMA) dampers installed in the bracings of the tower. The cyclonic wind field is modelled as per the guidelines of the World Meteorological Organization, and the Harris power spectral density function (PSDF) is used to characterize the fluctuating component of the cyclonic wind velocity. Nonlinear time history analysis of a single circuit lattice transmission tower is carried out under the cyclonic wind load time histories generated for each node of the tower. Results indicate that the recentering and energy dissipation properties of superelastic SMA bar dampers are capable of significantly mitigating the tower’s response to cyclonic wind loads.