Modelling of Aeolian Vibrations of Bundled Conductors

This section covers the effectiveness of analytical methods based on the EBP and a shaker-based technology for the design and/or verification of the damping system of conductor bundle spans with respect to aeolian vibrations. This study is based on an analysis of the available technology and on the results of benchmarks: an analytical–analytical benchmark and an analytical–experimental one are used for the evaluation relevant to aeolian vibrations. The two benchmarks assessed within the Working Group allowed to understand the main differences among the models presently adopted in the field of conductor vibrations to understand and control aeolian vibration. The analytical–analytical benchmark showed that the computed vibration amplitudes have a very similar trend even if some differences in the models are present. Regarding the experimental-numerical benchmark, the numerical results generally exceed the experimental ones and then they are conservative, at least at low frequencies. However, it must be pointed out that, generally, when dealing with twin bundles, numerical results appear to be less conservative in respect to the experimental data. The sensitivity analysis demonstrated that a non-negligible influence in the assessment of conductor behaviour, when dealing with aeolian vibrations, is given by the introduction of tension differentials and variable wind turbulence with wind speed. Clearly, it is not straightforward knowing the real value to assign to the turbulence and to the tension differentials when the bundle behaviour for aeolian vibrations must be analysed. Future work is needed to achieve better knowledge on this issue, considering the comparison between measurements on a real line and analytical results.