Identification of large amplitude wind-induced vibration of ice-accreted transmission lines based on field observed data

This study presents a method for identifying the periodic galloping response and random gust response of transmission lines based on restricted field observed data, and for separating the major galloping component from the mixed mode of gust and galloping vibration. Time-averaged characteristics of wind-induced vibration are discussed based on spectral analysis, and non-stationary characteristics are considered to identify the wind-induced vibrations quantitatively by applying Prony's method in a piecewise fashion. By applying highpass filter, the major galloping response component is separated from the mixed response modes of galloping and gust response, and characteristics of the separated major galloping response component are compared with those of total response. Results of these analyses show that there is a possibility of having large amplitude galloping as well as gust response in in-plane vertical motion in ice-accreted transmission lines. The applicability of the random decrement method to estimate the existence of the periodic correlated galloping component is also discussed.