Fretting fatigue life assessment of overhead conductors using a clamp/conductor numerical model and biaxial fretting fatigue tests on individual wires

The fatigue life of overhead conductors is usually evaluated through experimental tests on clamp/conductor assemblies. Some recent studies aim to estimate the fatigue life of conductors using uniaxial tests on individual strands. This paper presents an innovative method for assessing the fretting fatigue life of overhead conductors combining the effect of both tension and bending loadings. It consists of coupling a numerical approach based on modeling the clamp/conductor assembly using the finite element method and an experimental one based on fretting fatigue tests on individual wires. A biaxial fretting fatigue test rig has been developed and validated through preliminary tests performed on 1350-H19 aluminum wires under uniaxial and an equivalent biaxial loading. Tension and bending loadings obtained from the numerical model were then applied on individual wires. Results showed a good correspondence with existing experimental data of the fatigue tests carried on the aluminum conductor steel reinforced (ACSR) Bersfort conductor with a metal-to-metal suspension clamp.