The International Electrotechnical Commission (IEC) just released a new international standard titled: "Overhead lines - Method for fatigue testing of conductors". IEC 62568. Edition 1.0 2015-07. www.iec.ch . It closely follows previous CIGRE and EPRI publications on this topic:
CIGRE SC B2 WG11 TF7 "Fatigue Endurance Capability of Conductor/Clamp Systems - Update of Present Knowledge" CIGRE TB 332, 2007, Paris.
EPRI Chapter 3 "Fatigue of Overhead Conductors, EPRI Transmission Line Reference Book: Wind-Induced Conductor Motion, 2nd Ed." EPRI, Palo Alto, CA, 2006