A Study of the Wear Behavior of a Rail Material

The rail track is one of the most important elements of a railway system. During the passage of trains, the rails are subjected to contact load that comes from the wheels of the train.  The railway track often fails in service due to wear caused by contact fatigue and other wear damage mechanisms that could also limit the life span of the railway infrastructure and railway vehicle. The aim of this research is to investigate the wear behavior of a railing material under the effects of variable vehicle loads, coefficient of friction, and running speed of the train. In this study, wear parameters (wear rate and wear volume) are analyzed by numerical modeling using SIMPACK. The wear behavior of Addis Ababa light rail transit rails was studied (on the straight track section of the north-south line) by considering variables: wheel load conditions of empty, full capacity, and overloading train; dry contact boundary friction condition (0.1 to 0.5 coefficient of friction); and typical light trail running speeds (0 to 70 Km/hr.). The increase of applied load, coefficient of friction, and running speed results in an increment of wear rate and wear volume of the track surface. From the study, it was found that the highest specific wear rate for the overload capacity of the train (fixed coefficient of frictions and speeds) is 1.271234 x 10-4 mm 3/Nm, while the lowest specific wear rate is 0.000453 x 10-4 mm 3/Nm. The highest specific wear rate occurred at the maximum operating speed of 70 Km/hr. T (fixed loading conditions and coefficient of frictions), while the lowest specific wear rate occurred at a speed of 20 Km/h. This shows that to increase the wear life of the rails in Addis Ababa light rail transit. It is imperative to use optimal loading conditions, a lower coefficient of friction (0.25 to 0.35), and a medium running speed. (20 to 40 Km/hr.).