Modélisation locale des conditions d'endommagement aux pinces de suspension des conducteurs de lignes de transport électriques : une approche intégrée à une stratégie d'analyse multi-échelle

Abstract

Overhead conductors of power transmission lines are constantly exposed to climatic loads, particularly Aeolian vibrations, which lead to cyclic bending loads at the suspension clamps. Due to the stranded geometry of the conductors, this leads to fretting damage mechanisms at the contact interfaces. This mode of degradation is complex and can, under certain conditions, rapidly lead to the initiation of cracks in the conductor strands, then propagate to complete failure. Identifying and preventing this damage is therefore one of the main challenges in assessing the residual life of conductors with greater precision. Although several experimental studies have been carried out on conductors, a refined prediction of their service life requires a detailed description of stress fields at critical contact zones, which numerical methods can provide. This research work therefore focuses on the development of a finite element numerical model to better describe local conductor damage conditions using a multi-scale modeling approach. The proposed approach first exploits a global numerical model of a clamp-conductor system to characterize local loading conditions, and relate them to the external stresses typical of Aeolian vibrations. Next, a new wire-scale modeling strategy is developed for the contact interfaces between the conductor and the suspension clamp, as the global analysis revealed them to be more critical. The local modeling proposed allows to describe the stress fields at the contacts, while considering the stranded geometry and multiaxial loading in the critical zone. Appropriate damage criteria can then be applied to predict conductor life. These modeling results are supported by experimental fatigue tests on ACSR Bersfort conductors within metallic suspension clamps.

Date	6 Aug 2024
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Sébastien Lalonde (Supervisor) & Sébastien Langlois (Co-supervisor)