Modelling of Aeolian Vibrations of a Single Conductor Plus Damper

It is well known that if the conductor tension (or, more precisely, the ratio between tension and conductor unit weight H/w) exceeds certain limit values, aeolian vibrations may cause serious conductor and fitting damage. This limit H/w value is generally exceeded on transmission lines and then it is established practice to protect conductors with suitable dampers. For new transmission line designs, it is important to know how much additional damping is needed to control aeolian vibration within safe levels. To this purpose, various researchers have developed computation methods, based on the EBP, to predict the aeolian vibration level of a conductor plus damper and then to allow for the selection of the suitable damping system: these methods use the damper dynamic characteristics as measured on a shaker. This section evaluates the computation methods, through direct comparison among them and with results obtained on an experimental span, with the final aim of defining the uncertainty of the considered methodology. The strains predicted by the different researchers exhibit considerable variability. Nevertheless, analytical methods based on the EBP and shaker-based technology can provide a useful tool for use in design of damping systems for the protection of single conductors against aeolian vibrations. It should be used with circumspection and be supplemented by references to field experience.