Damping properties of non-conductive composite materials for applications in power transmission pylons

Abstract

This study aims to characterize the fibre direction dependent damping properties of non-conductive composite materials to be used in newly designed electrical power transmission pylons, on which the conducting cables will be directly connected. Thus, the composite structure can be designed both to insulate and to act as a damper to avoid for example conductor line galloping. In order to predict the damping of the composite materials, a comprehensive analysis on a representative unidirectional laminate was carried out. The fibre direction dependent damping analysis of glass and aramid reinforced epoxy and vinylester, partly reinforced with nanoclay or fibre-hybridized, was investigated using a Dynamic Mechanical Thermal Analysis and a Vibrating Beam Testing procedure for five different fibre orientations (0°, 30°, 45°, 60° and 90°). The focus was on damping behaviour evaluation at low temperatures (−20°C and 0°C) and low vibration frequencies (0.5 Hz, 1 Hz and 2 Hz), in order to represent the environmental conditions of vibrating conductor lines during. The prediction of the damping behaviour for coupon-level-specimens with three balanced laminates was successfully carried out with a maximal deviation of maximal 12.1%.