No abstract

The research on improvement of methodical approaches to definition of the probable reasons of infringement of conditions of stability of freight cars from derailment is carried out. Using a basic computer model of the dy-namics of a freight car, the influence of the characteristics of the technical condition of their running gear and track on the indicators of empty cars stability from derailment was studied through the computational experi-ment. The article presents the main statements of the research methodology, which provides the analysis of probable causes of derailment of freight cars by conducting a series of numerical experiments with logging the progress of calculations and saving the results. Factor analysis was used to interpret the calculated data with an assessment of each of the factors influence or their combination on the probability of derailment. The developed procedure of the simulation experiment provides a step-by-step study of the freight cars derail-ment conditions, including factors structuring and ranking, development of experimental plan, calculating coef-ficients of wheel pairs resistance to derailment from rails, provided that the wheel flange rolls onto the rail head, and determining the degree of influence of relevant factors on the dynamic stability of cars from derailment. A comparative analysis of the stability of cars in rail tracks was performed using the introduced concept of the combined coefficient of stability of wheel pairs against derailment. Determining the probable causes of car derailment is based on scanning the parameter field. The results of the parametric study revealed the degree of influence on the freight cars stability of running gear technical condition characteristics. In particular, it is determined that the most dangerous in terms of stability loss of empty cars in the track is the exceeding of the wedges of the vibration dampers.

No abstract

Issue related to ensuring safety of technical operation of fl at cars for high speed containerized transportation by way of using new types of running gear is considered in the paper. Because of principal drawbacks of widely used bogies of freight cars possible use of axle box suspension bogies is considered for the equipment of high speed fl at cars. Taking into consideration highly effi cient application of mathematic simulation for the determination of dynamic performance of railway cars appropriate computer models were developed for the estimation of the conditions related to ensuring safe motion of fl at cars. It was revealed as result of the simulation that in case of stability of wheelsets against derailment condition of safe operation of a fl at car equipped with axle box suspension bogies is satisfi ed at travel speeds up to and including 150 km/h whereas safe travel of a fl at car equipped with conventional bogies is ensured at travel speeds up to but 100 km/h. Th is conclusion gives bases to recommend equipment of fl at cars for high speed containerized transportation with axle box suspension running gear.