Evaluation of the effect of rail pad stiffness and wheel polygonization on the dynamic behavior of corrugated railway tracks

Oscillatory damage or irregularities on the rails and wheels of railway systems significantly affect the system’s performance. Mitigating these defects is a task that concerns operators worldwide. In this work, a methodology is proposed to study the effect of pad stiffness and low-order wheel polygonization on the dynamic behavior of a corrugated railway track. Corrugation was measured using an accelerometer mounted on a grinding vehicle, and it was modeled as a wave-type excitation on the rail. Displacement probe-based methodology was used in wheel eccentricity test and the polygonization was considered by incorporating the local radius at every degree of rotation for the studied wheels. The methodology considers different static stiffness values of the pads, and after several evaluations, the most suitable pad was selected to mitigate the effects of the oscillatory defects. The performance of the selected pad was verified under different track stiffness values (measured using the video gauge method), this pad with a stiffness of 179 kN/mm presented the best performance for most speed scenarios with an increase of 71% when corrugation and wheel polygonization were considered for the simulation conditions (small curve of radius 304 m, corrugation wavelength of 45 mm, speed of 80 km/h). Finally, anomalous behaviors related to system resonance between the track and vehicle were analyzed. The evaluation showed that a pad stiffness of 60 kN/mm causes a resonance increasing 513% the accelerations when wave defects are present.