Impact Of Wind-Induced Vibrations On Aluminum Conductor Fatigue: A Novel Testing Approach

Abstract

In transmission lines, wind-induced vibrations, like high-frequency wind vibrations and low-frequency galloping phenomenon, can cause fatigue damage and failure, particularly in aluminum conductors, which have greater flexibility. Wind loads are variable forces applied by the wind to structures, including conductors. These dynamic wind loads vary with weather and altitude where the conductors are located, causing mechanical dissipation energy due to wire friction, particularly in contact zones. To ensure stability and safety, these loads and the damping effect must be taken into account when planning electrical transmission systems. The aim of this study is to investigate the impact of wind loads on the conductor's self-damping characteristics using a new approach to self-damping testing. Indeed, a self-damping test was carried out at the University of Brasilia's fatigue laboratory on 838 MCM AAAC 1120. The test bench was operated at frequencies ranging from 15.25 to 35.55 Hz, with the catenary parameter H/w = 2143 m, representing the ratio between the initial horizontal tensile load (H) and the conductor weight (w) per unit length. The power dissipated per unit length was calculated using the power method. It uses a methodology that allows the dissipation of mechanical energy to be measured accurately. The analysis revealed that higher frequencies lead to greater energy dissipation. Higher normalized amplitude with respect to the conductor diameter (Y/D ratio) lead to greater dissipation at the same frequency. The increase follows a power-law behavior, which is typical of vibration systems where the dissipated energy depends on frequency and amplitude.