This is a repository copy of Laboratory assessment of arc damage in railway overhead contact lines with a case study on copper-silver and low oxygen content copper.

This is a repository copy of Experimental investigation on the arc damage and fatigue crack initiation risk of copper-silver contact wires.

Özet: Bu çalışmada yeni yaprak yay tasarımları için mümkün olan en az sayıda prototipin üretilmesini ve seri üretime en kısa sürede geçilebilmesini sağlayacak bir yöntem geliştirilmesi amaçlanmıştır. Yorulma ömrünü belirlemeden önce parabolik yaprak yay tasarımına ve yorulma ömrüne etki eden faktörler incelenmiştir. Tek katlı bir parabolik yaprak yay için sonlu elemanlar modeli üzerinde gerilme ve yorulma analizleri Ansys Workbench 14.5 ve Ansys nCode Design Life 14.5 programları ile gerçekleştirilmiştir. Elde edilen sonuçlar fiziksel test değerleri ile karşılaştırılıp yorumlanmıştır. Yapılan yorulma ömrü çalışması ağır ve hafif ticari araçlarda kullanılan yaprak yayların tasarımlarında prototip üretim sonrasında parça üzerinde uzun süren denemeler olmadan, yorulma ömürlerine sonlu elemanlar analizleri ile ulaşılmasının mümkün olduğunu göstermiştir.Abstract: In this study the main goal is to produce a new method which provide to minimize manufacturing and test periods for leaf springs. Before fatigue life determination of leaf springs, parameters which effect on fatigue life prediction and parabolic leaf spring design have investigated. Parabolic leaf spring's FEM model'sstress and fatigue life analysis have substantiated with Ansys Workbench 14.5 and Ansys nCode Design Life 14.5. The results obtained were verified by comparing the value of physical tests. This finite element fatigue life studies have proved that it is possible to reach fatigue life prediction of the leaf spring used in light and heavy commercial vehicles without longtime experiments tests on track after prototype manufacturing.

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.

Railway overhead line electrification (OLE) is used for providing continuous power to the trains throughout catenary wires and the current collector device of the pantograph. The interaction of contact force exerted by the pantograph and contact wire is an important topic in regulating OLE dynamics. OLE components are subjected to fluctuating contact forces due to the trains running with high speed, therefore, it is important to estimate service life of contact wires and pantograph carbon collectors by considering contact wire/pantograph interference. This study performs a number of contact force and stress/strain analysis of standard OLE designs used in Europe, Series 1, Sicat S1.0, Sicat H1.0, Re250 and EAC 350, with finite element method. The results establish a link between stress levels and contact force in the contact lines depending on the design parameters of contact wire type, pretension, span-length, and contact wire material. Understanding the bending of the contact wire due to the contact force will help to predict potential failures in mainlines and extend our knowledge of safety and reliability of various OLE design parameters.