Determination of the form of loss the freight cars stability taking into account the gap in the rail track

Abstract

Derailments of freight cars occur for various reasons: breakdown of equipment or individual parts; maintenance deviations in the track superstructure; incorrect order of passing and making-up trains; violation of normal dynamic conditions, which occurs due to hunting and unfavorable traffic conditions on a curved track section. In order to avoid derailments and ensure a stability coefficient, the restrictions expressed using certain indicators are set. These indicators determine the conditions for lifting the wheel above the rail head, overturning the rail and widening the railway track. One of the most widely used restrictions is the restriction expressed in terms of the ratio of the lateral force acting on the wheel to the vertical force.Rolling stock derailment when the wheel flange is rolled onto the rail head, as a rule, is facilitated by longitudinal compressive forces.The presence of longitudinal forces in the train results in unloading the wheels moving along the outer rail line, and overloading the wheels moving along the inner rail line.The stability loss of freight cars as part of a train should be divided into two stages: stability loss of the body on suspension springs and the stability loss of the wheel set, which results directly in the derailment.
 The work is aimed to study the influence of longitudinal quasi-static compressive forces arising during stationary modes of train movement on the form of freight cars’ instability. The relevance of this study relates to the need to control the longitudinal forces arising during the train movement, taking into account the increase in speeds, masses and lengths of trains, especially freight trains, by in the locomotives power increase. The use of the above methodology will improve the stability of freight rolling stock, justify the cause of derailment, as well as develop and put into practice technical measures to prevent the lift of the carriages, widening and shear of the track.