The wheel/rail interface is perhaps the most important aspect of a railway network as what happens here dictates train performance and whether it can meet timetable requirements; safety, particularly in low friction conditions and it drives damage mechanisms in wheels and rails which impacts on maintenance.
The contact is typically the size of a 20p coin, so a whole train is supported by a remarkably small area in total. This means that contact stresses are very high. These, along with shear in the contact, drive the creation of a deformed layer on the surface of the wheels and rails that drives damage mechanisms. The contact is extremely complex. Stress and slip conditions vary constantly as a wheel progresses down the track as the relative position of wheel on rail changes. It is also an open system so is affected by natural contamination: leaves, water, snow etc. There are a number of applied products on wheels and rails as well for friction management purposes such as sand; top-of-rail friction modifiers and grease lubricants in curves. This makes the tribology of the wheel/rail interface very hard to study and model.
The papers in this special edition resulted from the 11th International Conference on Contact Mechanics and Wear of the Rail/Wheel System held in 2018 and hosted by TUDelft in The Netherlands. They cover a range of diverse areas relating to the wheel/rail interface including measurement; experimental work and modelling across the key topics of friction; contact stress and damage caused by wear and rolling contact fatigue.
All featured articles in this special issue are free to view until March 31st, 2021, exclusively via this page.
