Dynamic wheel-rail interaction at high speed based on time-domain moving Green's functions

•A time domain interaction model presented for fast rotating wheelsets and a periodic track.•Time-domain moving Green's functions derived for fast rotating wheelsets.•Wheel-rail force frequencies investigated for typical excitation scenarios.•Importance of wheelset rotation demonstrated.•Frequencies generated by presence of multiple wheelsets identified. Many issues of concern in the railway industry are fundamentally caused by dynamic wheel-rail interaction. To deal with these issues, the characteristics of the interaction must be accurately predicted and fully understood; this becomes even more challenging when the train speed is high. Although much research has dealt with wheel-rail interaction, some aspects related to high speed trains still need to be further addressed. In this paper, an approach based on time-domain moving Green's functions developed previously is extended and employed to calculate wheel-rail forces. The extension includes consideration of the flexibility and rotation of the wheelset by incorporating the associated time-domain moving Green's functions in the method. These are derived from the corresponding receptances by applying an experimental modal analysis technique to the calculated frequency response functions. Cases are considered for a single, or multiple, wheelsets rolling over a track represented as an infinitely long periodic structure. Wheel-rail forces are calculated for a set of parameters typical of the Chinese high-speed railway and for a number of typical excitation cases, including purely parametric excitation on a smooth rail, an indentation on the rail, wheel polygonisation and rail corrugation, for the purpose of revealing the frequency content of high-speed wheel-rail interaction. Effects of the wheel rotation on the wheel-rail forces are studied and comparisons are made between a single wheelset and multiple wheelsets.