An experimental study of high speed wheel-rail adhesion characteristics in wet condition on full scale roller rig

Abstract

Adhesion at the wheel-rail interface is a key factor determining stable running conditions and safety during train traction and braking. The wheel-rail abrasion of EMUs often occurs when the adhesion force is insufficient. This paper presents experiments performed on a high-speed full-scale roller rig of wheel-rail interface to simulate the low adhesion problem of high-speed railway in wet condition. Tests were conducted to study the adhesion characteristics at high speed under water lubrication. The influential factors on the high-speed wheel-rail adhesion coefficient are investigated, which include water spray amount, roughness of wheel-rail contact surface, running speed, water temperature and axle load. In the adhesion tests, water was sprayed on the wheel-rail contact interface at 0–250 ml/min, the roughness of the wheel-rail contact surface Ra was set within 0.30 to 1.1 μm, the test running speed range was 40 to 400 km/h, the temperature of water changed from 0 to 60 °C to simulate the effect of temperature on the adhesion coefficient and the axle load ranged from 8 to 16t. The law of influence on wheel-rail adhesion characteristic curves at high speed was revealed and explained based on the test results, which can be helpful to the design and optimization of the anti-slip control device in brake and the rotation/slip control device of the traction wheel of EMUs.