Wheel-rail dynamic interaction due to rail weld irregularity in high-speed railways

Rail weld geometry irregularity is one of the main excitation sources for vehicle-track coupled dynamic system, and it has a direct effect on the wheel-rail dynamic interactions, which are responsible further for the wheel-rail noise, railway component damages, and track deteriorations. In many previous studies, the rail weld irregularity was usually modeled as a single or composite concave cosine wave based on field investigations on traditional railway lines or researchers' experiences. These investigations were mainly concentrated on the maximum value of the rail weld irregularity. However, the geometrical shape was usually ignored. In this paper, a series of rail weld irregularities measured on Beijing-Shanghai high-speed railway passenger-dedicated line in China are presented. Based on the analysis of the measured rail surface geometry in the weld zones, some typical theoretical models of the rail weld irregularity are established. Then, the effectiveness of the established rail weld irregularity models are demonstrated for dynamic evaluation of the rail weld irregularity in high-speed railways by comparison between the wheel-rail dynamic responses excited by the measured and the modeled rail weld irregularities, respectively. Finally, the influences of different rail weld irregularities on the wheel-rail dynamic interactions are investigated using the vehicle-track coupled dynamics model and the established rail weld irregularity models. The results are expected to be capable of providing references for the analysis and evaluation of the rail weld irregularity in high-speed railways.