On the modeling and analysis of a vibration absorber for overhead powerlines with multiple resonant frequencies

Stockbridge dampers are primarily used to suppress or reduce Aeolian vibrations of transmission lines. The number of resonant frequencies characterizes the effectiveness of the Stockbridge damper. Aeolian vibrations refers to the vibration of conductor cables in the range of 3-150 Hz. Unlike the primitive Stockbridge damper which has only two resonant frequencies, the asymmetric Stockbridge damper exhibits up to four resonant frequencies. The numerical simulations and parametric studies conducted previously showed a correlation between the increase of natural frequencies and the change in the geometry of the counterweight. This paper presents an analytical model of a novel Aeolian vibration damper with an increased number of resonant frequencies. The analytical model is used to deduce the resonant frequencies of the damper. A 3D finite element model is developed to validate the analytical model. The natural frequencies and the subsequent mode shapes of both analytical and finite element models are presented. Experiment is conducted to validate the proposed models.