Numerical investigation on wheel-rail impact contact solutions excited by rail spalling failure

Abstract

Rail spalling is a typical form of wheel-rail rolling contact fatigue (RCF), and is a difficult problem that has always existed in railways. Once the wheel rolls across the spalling failure area, there will be a violent dynamic wheel-rail interaction. This paper presents an explicit high-speed 3D wheel-rail rolling contact transient explicit finite element model that considers local rail spalling failure. The dynamic wheel-rail interaction under the condition of differentspalling lengths and contact stress states, as well as plastic strain of the rail when the wheel rolls across the rail spalling, are calculated using the theory of transient wheel-rail dynamics. In addition, the time–frequency analysis is carried out to obtain the distribution characteristics of dynamic response signals such as axle box acceleration, rail vibration acceleration and dynamic vertical wheel-rail force in time domain and frequency domain.Furthermore, when the vehicle travels at a high speed, the speed and radius of the wheelhave little influence on the dynamic vertical wheel-rail force, or on the wavelet energy peak and frequency. The effect of the mutual dynamic correlation is small. But the dynamic vertical wheel-rail force, along with wavelet energy peak and frequency, increase in an approximately linear fashion with the impact acceleration of wheelset and the length of spalling failure. These results can be used to guide the dynamic detection of local defects on rails.