Analytical method for predicting the quasi-static buffeting response of transmission conductor under non-stationary winds

Most failures of transmission towers are attributed to the actions of severe thunderstorm downbursts and tornadoes with nonstationary characteristics. This paper presents an analytical framework for predicting quasi-static buffeting response of a conductor when subjected to the non-stationary wind excitations. The analytical solutions of nonlinear time-varying mean response as well as influence functions around the static equilibrium are derived for arbitrary spatial and temporal variations of the mean wind speed. The time-varying standard derivation (STD) of response is directly calculated using the influence function and correlation function of wind fluctuations. The framework also permits calculation of probability distribution of extreme response and peak factor from the time-varying mean and STD of response. The efficiency and accuracy of the framework are demonstrated through comparison of response predictions from a nonlinear dynamic finite element (FE) analysis.