Overhead conductors

The aim of this chapter is not only to introduce the classical S-N based approaches to design overhead conductors against fatigue due to aeolian vibration but also to present recent experimental results and analyses on the effect of (i) the tensile load, (ii) the catenary parameter (H/w), (iii) the use of elastomeric (CGS) type clamps, and (iv) the temperature on the fatigue life of different families of conductors (AAC, AAAC, ACSR, ACAR). Results show that these variables can have a significant influence on conductor’s life. Further, as the durability of such conductors is essentially related to damage accumulation in wires due to fretting fatigue, the chapter also proposes a methodology towards a multiscale fatigue analysis for these components. It presents a nonlocal multiaxial fatigue criterion that incorporates the stress gradients beneath the contact surface of the critical wire, which is validated by wire-on-wire test data on AA1350-H19 and AA6201-T81 alloys. These tests are conducted on a two-actuators hydraulic fretting rig. Life estimates within factors of 3 and 5 have been achieved.