Modelling the Flexural Hysteresis Behaviour of Bretelle Dampers Based on a Quasi-Static Bending Test

Bretelle dampers are made of slack conductor pieces that are used to mitigate aeolian vibration amplitudes. Under cyclic and dynamic excitation, inter-strand friction in slack conductors causes a significant flexural hysteresis leading to the dissipation of high amounts of energies. The objective of this work is to study the flexural hysteresis of three types of slack conductors based on quasi-static bending tests and to reproduce their nonlinear hysteresis behavior using two different approaches; an analytical model using a linear Euler-Bernoulli beam coupled with a Bouc-Wen model, and a finite element model using a superposition of multifiber beam elements with material nonlinearity. The parameters of both models are identified based on the bending test results for different levels of deformation. The developed models in this study can provide a fast tool for manufacturers to identify the dynamical behavior of slack conductor and to optimize their damping properties. Furthermore, the bretelle damper model can be integrated into a conductor model in order to study the vibrational behavior of transmission lines equipped with bretelle dampers.