Investigation of the longitudinal dynamics of a train based on a discrete model

The article discusses the causes of freight train breakage, which occur due to a number of reasons, but one of the main ones is a sudden transition from a compressed state to a stretched one. This becomes possible due to a malfunction of the braking system (leaks, blockage of the calibrated air distributor openings) and, of course, the train control technology. Train control technology depends on the characteristics of the traction and braking systems of the rolling stock, as well as on the experience and skill of the driver in difficult track conditions. The dependence of breaks on the season has been established due to the frequent jamming of the wheelset and a decrease in the strength characteristics of the metal of the coupling. In this regard, it is important to solve the problems of train dynamics to determine the rational methods of train driving. The existing methods of model construction are considered. The results of studies of the longitudinal dynamics of a train based on a discrete model are presented. The calculation was performed for two modes: braking and traction, in the time domain, for which the forces acting on wagons and locomotives were determined in advance, depending either on time (traction and braking force) or on the speed of movement (drag force). As a result of mathematical modeling, the values of displacement and speed for each wagon with a multiple of five were obtained. An analysis of the results showed that significant longitudinal forces occur in the middle of the train during braking. The resulting model allows us to study the forces acting on trains with empty wagons, which require relatively minor forces to squeeze out of the train.