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V.3(47), 2021
41-50The article describes trends in the technical development of fixing devices for containers, called a "fitting retainer". Containers have gradually conquered the transportation market in the USA, Europe and Asia. And each means of transport: road, marine and railway one needed devices to fix containers, because all participants of the transportation process are responsible for the safety of goods. In the period of the appearance of container transportations, commercial agreements between operators and transport companies played an important role, influencing the unification of overall dimensions and weights of containers and transported goods, which was a prerequisite to create fittings for containers and, as a result, fitting retainers for all means of transport. The domestic regulatory framework also required updating, monitoring a large number of flat wagon manufacturers and taking into account severe operating conditions of containers throughout the entire railway network. With the rapid development of the container transportation market on long routes from China to Europe and the transition to the technology of accelerated container train sets based on high-speed flat wagons, it becomes necessary to solve the issue of wind protection of empty containers and low loaded containers, taking into account the speed of up to 140 km/h. Well-known technical solutions from different manufacturers to fix containers in retainers of special shapes and with additional fixing through a retainer hole have been analyzed. An original technical solution of the fixing device is proposed, performed in the flat wagon opposite each fitting to install the container. By turning this device using man power, each corner of the container can be fixed to prevent empty containers from falling (tippling) from flat wagons when exposed to wind loads, which meets requirements of safety, operation and reliability of fixing the container in the flat wagon. -
V.3(43), 2020
76-85The problem of the assessment of the continuous welded rail track stability at its thermal elongation is considered in this paper. The method for determining the stress-strain state of various elastic objects developed by the specialists of JSC “VNIKTI” is analyzed on the example of a rail of a continuous-welded track section. The essence of the method is to determine the dependence of the natural frequencies of rail vibrations on the applied longitudinal force. As a means of obtaining such a dependence, a modal analysis of a track section model carried out using the finite element method was chosen. The methodology for calculating the natural frequencies of rail vibrations and the description of the created model of the track section and its properties are presented in the paper, the contact interactions of the model elements and boundary conditions are defined in it. Calculations for determining the natural frequencies and modes of rail vibrations are performed, the first four modes of rail vibrations obtained by calculation and experimental methods are shown. The assessment of the adequacy of the created model of the track section is carried out by comparing the natural frequencies and modes of rail vibrations obtained by calculation, by modal analysis methods and experimentally when measuring vibrations on a full-scale object - assembled rails and sleepers, having a similar design compared with the model. It was decided to use the distance between the vibration nodes as a criterion for comparing the obtained modes of natural rail vibrations. The first mode of vibration is selected for further studies. Calculations were carried out and the dependence of the natural frequency of the first vibration mode of the rail on the longitudinal force applied to it was obtained using the created model of the track section. The obtained dependence can be used in the method proposed by the specialists of JSC “VNIKTI” in order to determine longitudinal force, applied to the rails on the full-scale section of the continuous welded rail track.