A new small sample test configuration for fatigue life estimation of overhead contact wires

Fatigue in railway overhead line electrification (OLE) contact wires can cause sudden catastrophic failures. The contact wire interacting with the pantograph both mechanically and electrically is subjected to tension and repetitive bending due to the pantograph contact force. Recently, fatigue failures of OLE have risen in prominence with increases in train speed. To address this a new fatigue test configuration has been developed. The study focuses on a method for testing the wire as a component enabling fatigue life evaluation of worn wires, or exploring the effect of installation damage, through component level evaluation of crack initiation and propagation. The new test configuration places a 400 mm-length contact wire in a combination of bending and pretension with realistic boundary conditions replicating service conditions for longer spans. The results are presented in a strain-life format to provide data for a wide range of potential service conditions.