Analysis of buckling failure in continuously welded railway tracks

Continuously welded rails (CWR) are sensitive to thermal and train loads which could destabilize the track and cause buckling. The study of track buckling in the literature, however, is mostly focused on static analysis of CWR tracks under thermal loads. Yet in reality, train dynamic loads in lateral, vertical and longitudinal directions can have a major impact on track buckling behaviour. Moreover, track and wheel defects can aggravate the dynamic train track interaction loads, and reduce the safety against track buckling. The aim of this paper is to have an in-depth comparison of static and dynamic track buckling by employing a multi-body train-track dynamic model and a 3D finite element track model. Various scenarios are elaborated, base scenario dealing with static thermal analysis, dynamic analysis for a steady motion of a wagon with constant speed, dynamic analysis for a wagon with defect free wheels during braking, and dynamic analysis for a wagon with out of round defect wheels during braking. For each scenario, a sensitivity analysis of relevant parameters is also presented. Based on the results, it is concluded that train loads can significantly change the buckling temperature, as well as the safe temperature. For a severe braking of a wagon with out of round wheel defect of order 3, buckling temperature is almost 5.5 degrees C less than that of the static case. The drop for safe temperature in this case is 6.7 degrees C.