Nonlinear numerical model with contact for Stockbridge vibration damper and experimental validation

The Stockbridge vibration damper is widely used in overhead transmission lines to reduce Aeolian vibration. Although a linear analytical model has been developed to interpret characteristics of the vibration damper, a much more detailed model is needed to investigate how the nonlinear factors of the structure affect its vibration characteristics. The paper presents a full-scale finite element model of the Stockbridge vibration damper, in which contact conditions are taken into account using the linear perturbation method. Relations between the contact conditions and mode frequencies were studied. It was proved that contact conditions between each two parts of the damper have significant influence on the stiffness of the whole structure. Results obtained from the numerical model compare well with those from the experiment. Finally, this numerical model was applied to investigate how the bonding material between the counterweight and steel strand cable affects the mode frequencies of the vibration damper.