Abstract: In order to compare the wheel wear evolution characteristics on different lines and its influence on the dynamic performance of EMUs, the wheel wear of EMUs on the same platform running on two high-speed lines A and B with a speed grade of 250 km/h was tested for a long time. Matching the measured wheel tread with the measured rail profile, the influence of wheel wear on the contact geometric interaction such as equivalent conicity, wheel-rail contact point distribution is compared and analyzed. A vehicle dynamic model was established by the multibody dynamic analysis software SIMPACK to study the evolution of vehicle dynamic performance and rolling contact fatigue damage with the evolution of wheel wear. The results indicated that the average wheel wear rate of line A was 0.05 mm/10 000 km, the tread wear was distributed in the range of -20～30 mm, showing hollow. The increase rate of equivalent conicity was about 0.006/10 000 km, as well as the wheel-rail contact point gradually draws close to the rail shoulder and there is obvious jumping phenomenon. The average wheel wear rate of B line was about 0.025 mm/ 10 000 km, which was distributed in the range of -35～50 mm was uniformly distributed. The equivalent conicity was stable at about 0.03, and there was no obvious change trend with the increase of operating mileage. The wheel-rail contact points within 10 mm always keeped the middle wheel tread in contact with the middle rail top, and the wheel-rail contact points were uniformly distributed. With the gradual increase of operating mileage, the dynamic performance of A line decreased slightly, while the dynamic performance of B line was basically stable. The wheel surface fatigue index of line B was less than the line A, so the possibility of rolling contact fatigue crack is less.

Key words: high-speed EMU, wheel wear, wheel-rail contact interaction, dynamic performance, rolling contact fatigue