Numerical and experimental procedures for determining characteristics of stockbridge dampers

Abstract

The Stockbridge damper is a tuned mass absorber used to suppress wind-induced vibrations on slender structures such as overhead transmission power lines. The lines vibrate due to wind motion and this causes fatigue failure to transmission lines usually at the suspension clamp where the maximum stress occurs. The fatigue failure in transmission lines can lead to outage of electricity. There are three types of vibration motions, that is, Aeolian vibrations, conductor galloping and wake-induced oscillation. This is a preliminary study of the characteristics of an asymmetric Stockbridge damper in order to establish the efficiency and reliability of the current dampers. Experiments were conducted on dampers according to IEEE 664 standards at the Vibration Research and Testing Centre (VRTC) at the University of KwaZulu Natal (UKZN). Experiments were also conducted on a modified vibrating damper. The mathematical model of a vibrating damper is also presented in this thesis and theoretical or computational results are validated by experimental results.