New approaches to modeling the stability of a long-welded rails in the environment of finite element analysis

Abstract

The article discusses the existing approaches to solving the currently relevant issue concerning the safe expansion of the landfill of a joint-free track with the prevention of counter ejection stability loss. The study has been conducted of the existing methods for assessing the stability margin of a seamless path, ranging from the simplest ones not requiring significant calculations, to methods implemented with the help of specialized software, their advantages, disadvantages and possible applications depending on the range of tasks to be solved. A jointless track section model made in the environment of finite element analysis is presented, optimal in terms of the range width of setting initial conditions and obtaining output data (results). The methods of leveling one of the most significant disadvantages of the finite element method are shown i.e./ avoiding the need to rebuild the model when changing the initial data due to the developed macro programs in the Visual Basic for Applications environment, greatly simplifying the process of forming models, as well as output and analysis of results. The work also shows a new approach for determining the parameters of the maximum permissible rail temperature excess, relative to the fixing temperature, based on modeling the ejection process, which allows to obtain stability parameters for any track structure. At the same time, using the methods of probability theory, the values of critical temperatures are calculated for the pre-selected criteria for assessing the stability margin of a jointless track, whose statistical relationship, when using modeling and empirical methods, is maximal, which makes it possible to obtain «conditionally empirical» values of the temperature increase of the rail lash allowed by the stability tolerance of the track.