Russian Federation
Russian Federation
UDC 629.4.027.51
Objective: to present the results of mathematical modeling of the dynamic impact on the railway track of a freight car wheel with two non-rejection size flat spots. To substantiate the frequent cases of false activations of automatic control systems that record excess loads from wheels, during visual inspection of which only defects that do not exceed rejection standards are detected. Methods: using the “wheel — rail” calculation scheme in the MATLAB environment, the influence of the flat spot depth, speed, and distance between defects on the impact load magnitude was investigated. The track model is represented as a beam on a Fuss — Winkler elastic foundation. To describe the impact interaction, a calculation theory adapted for several sequentially located flat spots was used. Results: the results showed that the combined impact of two non-rejection size flat spots can lead to dynamic loads comparable to or exceeding the impact of a single rejection size flat spot. Critical speed ranges (40–65 km/h) and distances between defects (50–100 mm) at which the impact is maximum have been identified. Practical importance: based on the analysis, it is proposed to consider the presence of multiple defects when standardizing the condition of wheelsets to reduce the negative impact on track infrastructure. Current regulatory documents donot consider the cumulative effect of multiple defects, which can lead to accelerated wear of the track superstructure, as well as to the failure of the wagon running gear.
railway transport, wheelset, flat spot, dynamic load, “wheel — rail” system, mathematical modeling, non-rejection defect, Pauk system (Automatic Derailment Control System), impact, track
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