An investigation into the effect of slip rate on the traction coefficient behaviour with a laboratory replication of a locomotive wheel rolling/sliding along a railway track

This paper investigates the effect of slip rate on the traction coefficient of the wheel/rail interface using a twin-disc machine under the replicated tribological and locomotive operating conditions. The traction coefficient decreases with increasing slip rate. The interface materials of the tested samples get less time to accumulate strain hardening, resulting in a lower increase in surface hardness under a faster slip rate. The running-in period is shorter under a higher slip rate, indicating that the surface micro-geometry of the interface materials reaches a steady state faster. The wear and traction coefficient outcomes of this research could be helpful in improving locomotive traction control systems, and in increasing the safety and maintenance efficiency of railway operations.