Fatigue safety evaluation of newly developed contact wire for eco-friendly high speed electric railway system considering wear

Since carbon emission level of electric railway system is much lower than that of automotive transportation, electric railway system has been known as eco-friendly and low-carbon transportation. Recently, to expand the use of such railway system, there is global tendency of developing high speed railway system. In parts of high speed railway system, contact wire which supplies electricity to railway vehicles is exposed to continuous wear and bending fatigue through the contact with pantographs of running railway vehicles. In the past, only wear life of contact wire was considered since it is known that wear life is shorter than fatigue life. However, after the report of the fatigue failure on contact wire of Shinkansen in Japan, bending fatigue of contact wire has become a very important issue to be considered for the safety of contact wire. In this paper, based on the fatigue damage evaluation process that Yamashita et al. suggested for pure copper contact wire, cumulative fatigue damage on Cu-Mg contact wire which is newly developed for 400km/h-level railway system was calculated, and fatigue safety factor on Cu-Mg contact wire at allowable strain condition was investigated. In addition, to simplify such tests, a simpler method to obtain cumulative fatigue damage on contact wire from standard tensile test result is suggested.