Applicability of rain flow method to fatigue life span estimation of overhead contact wire

Abstract

The rain flow method has been put forward as a method for waveform counting to estimate what the fatigue life span would be under actual waveform stress. The authors carried out experiments to test its applicability to hard drawn copper contact wire. In order to consider the effect of mean tensile stress when applying the rain flow method it is first necessary to define the fatigue life span properties for the various mean tensile stresses. The authors confirmed that these estimations can be found using fatigue test results from hard drawn copper contact wire placed under two types of mean tensile stress condition. The authors then conducted six fatigue tests to investigate the applicability of the rain flow method. The actual measured fatigue life span in tests generally exceeded estimations The rain flow method may therefore conceivably be used to derive a method for safe estimation of fatigue life.