6-11In this paper analyzed the design of cast and weld side frames three-piece bogies. The directions of further improvement design side of a bogie frame.
22-32To increase the speed of the cargo delivery, freight wagons are being developed, intended for the design speed of 140 km/h. One of the important parts of a freight wagon is the bogie, the design of which determines the wagon dynamic behaviour. The bogie of such wagons uses a frame of a rigid design, which is susceptible to antisymmetric loads. The analysis of standards has shown that the strength test during designing a rigid bogie frame under the impact of maximum antisymmetric forces that may occur in operation when a wheel derails is not required, which can lead to a residual antysymmetric deformation of the bogie frame. Theoretical research is performed to estimate the impact of the residual antisymmetric deformation on traffic safety using the wheelset safety factor against derailment. The research results have shown that the bogie frame residual deformation leads to a load redistribution on the wheelset axle journal, which, in terms of the impact on the wheelset safety factor against derailment, is similar to the wagon rolling motion. The wagon rolling motion affects the reduction of the wheelset safety factor against derailment to a greater extent than oscillations during pitching and bouncing. Thus, the permission to operate wagons with the antisymmetric residual deformation of the bogie frame without its non-destructive testing can lead to traffic safety violation. In order to ensure the traffic safety of wagons with bogies having rigid frames and reduce economic losses at the design stage, bogies strength depending on the action of antisymmetric forces should be estimated.
30-36The results of the experimental study of the termal cycle of many-electrode welding of the solid wheel`s comb and its influences in work upon structurization in zone of the termal influence are presented.
Justification of design parameters tooling for repair of parts rolling stock with regard to dimensional relationships assembly unitsThe article describes the case of using the dimensional coordination of the working surfaces of housings of the vehicle-axle boxes of freight cars in the truck mod. 18-100 to determine the design parameters of the technological tools used to perform the machining operation surfaces after coating to ensure wear compensation. The parameters of technological devices grounded. Powered generally constructive solution.
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.
77-85In this article, the problem of assessing the stability of a continuous welded rail track during its thermal elongation is considered. The article considers the method of determining a stress-strain state of continuous welded rails proposed by specialists of JSC “VNIKTI”, which is based on the use of the dependence of natural frequencies of rail vibrations on the applied longitudinal force. Such a dependence can be obtained with the help of the calculation method using a finite element model of a track section. The reliability of such a dependence can be assessed by comparing the results obtained using the calculation method with the actual values of natural frequencies of rail vibrations, depending on the longitudinal tensile and compression force applied to a full-scale facility. The track panel is chosen as such a facility. In order to obtain the actual dependence of natural frequencies of rail vibrations on the applied longitudinal force, a specialized test bench is developed. The development of the test bench included designing the test bench elements and creating finite element models of main load-bearing elements of the test bench - a stop, support and traction, as well as their subsequent strength calculation to confirm the operability of the selected design under necessary loading conditions. The strength is assessed using the safety factor for the yield strength. Calculations using the finite element method have shown that the test bench design has sufficient strength. The developed test bench will allow performing tests for the purpose of the verification obtained using the calculation method of the dependence of rail vibration frequencies on the longitudinal tension and compression force applied to it, as well as for testing the proposed method to assess the rail longitudinal force during its thermal expansion.
Example of the methods to evaluate conditions and reserve of transverse stability in cwr curves under abnormal track maintenanceExample of the methods to evaluate conditions and reserve of transverse stability in CWR curves under abnormal track maintenance is discussed in the article. The author presents the results of the research of this method and also its positive effect is described.