The Effects of Wind Induced Conductor Motion on Accreted Atmospheric Ice

Galloping of transmission lines creates some cyclic stresses in the conductor and accreted atmospheric ice covering the conductor, which may result in ice failure leading to shedding. Attempts have been made in this research to estimate these cyclic stresses, and experimental tests have been conducted to study their effects on atmospheric ice. First, galloping of an ice-covered conductor was simulated by appropriate modification of existing models for bare conductors submitted to galloping. Then, the results of simulation were applied as input for a new model developed using ABAQUS. The results show that the layers of atmospheric ice at the top and bottom of the conductor endure maximum stress. The results of experimental tests with increasing cyclic stress show that ice does not break during galloping at wind velocities below 4.5 m/s. The tests under cyclic loads with a constant amplitude reveal that the ice does not fail under stresses corresponding to wind speeds of 3 and 4 m/s, and sometimes fails under stresses arising at a wind speed of 5 m/s.