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This article deals with computer analyses of output quantities of a railway vehicle depending on changing of parameters of suspension system. A passenger car was chosen for dynamic analyses. An analysed passenger railway vehicle uses two stage suspension system composed of coil springs and hydraulic dampers. Stiffness of coil springs of primary and secondary suspensions were defined for two states and its influence on output values in terms of quality and quantity was evaluated. As output variables, values of forces in a wheel/rail contact and accelerations in several locations on a wagon body floor were chosen. Values of forces in a wheel/rail contact indicate dynamic response of a railway vehicle running in terms of running safety and values of accelerations serve as important input for evaluation of passenger ride comfort.

The railway transport network is currently in a quite big expansion. Therefore, railway tracks are modernized and the attention is given also on the technical state of rail vehicles, which operate on them. However, it may happen that the wheel surface is damaged. One of the most common reasons of wheel damage is too much braking, which results to the wheel-flat formation. This article is focused on the evaluation of the influence of a rail vehicle running on the railway track, which a wheel is damaged by the wheel-flat. Investigation of these negative effects was performed by means of simulation computations. As evaluating parameters, values of the wheel force in the contact of the rail and wheel with a flat where observed.

In this article the strength analyses of weights boxes are presented. Boxes are designed as a welded steel structure at which weights with total mass almost ten tons are stored in them. These boxes are an integral part of a mechanism intended for calibration of the mass measurement device. The article contains on one hand the basic scope of the theory of elasticity and strength analysis and on the other hand the numerical computations of the structure by using the Finite Element Method. Based on results the structure of weights boxes was modified in order to satisfy the defined safety factor.

The repeatability of rail wheel damage measurements is considered in this study. The authors investigated the measurement repeatability of vertical force dependence on wheel-rolling surface damage nature and suggested ways to reach higher repeatability. To investigate wheel-rolling surface damage impact on vertical force measurement repeatability, the results of measuring forces with different measurement systems were compared first. Another critical issue was estimating the deviation field for the measured force values. The box and whisker principles were used. Different types (shapes) of rail wheel damages and rolling stock operating conditions were examined by field tests. The article presents the dependence determined by the authors, and how the repeatability of the wheel damage measurement depends on the speed of the rolling stock. [ABSTRACT FROM AUTHOR]

In certain conditions rail vehicles wheels can be during operation damaged. Then, the profile of wheels is no longer circular, but it is changed depending on the type and severity of defects. When such rail vehicle with the damaged wheel operates, the quality of a ride comfort for passenger is degraded. This article is focused on the assessment of ride comfort for passenger based on results obtained from dynamic analyses. Simulations and calculations were carried out in commercial multibody software. In our research we considered one type of the railway wheel untrueness – wheel-flat. This type of wheel damaging is relatively common and has such influence on the ride comfort for passenger worsening, which needs to be detected and investigated.

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The article discusses the problem of railway safety management and the criteria for evaluating the traffic risk described in various scientific publications. The research aims to assess the risk posed to railway infrastructure objects and to create a model for safety risk evaluation. The research on the traffic safety risk with respect to the infrastructure of the rail transport system was divided into three stages. The Plan–Do–Check–Act (PDCA) model can be used for investigating the problem of managing railway traffic safety risks in the Lithuanian railways. The main threats to railway infrastructure objects are defined, and the catalogue of technical parameters of level crossings of the Lithuanian railways is presented. The maximum allowable train speed, the intensity of railway and road traffic, as well as the size (width) and visibility of level crossings from the train driver’s cab are chosen as the main criteria for evaluating the vulnerability of a level crossing. The logistic regression method has been applied to rank and assess the safety of level crossings of the Lithuanian railways. The validity of the model developed in the present work for assessing traffic safety risks at level crossings of Lithuanian railways is about 86%. The suggested risk evaluation model is flexible and can be easily adapted for the evaluation and monitoring of safety risk of other elements pertaining to railway infrastructure. Finally, the basic conclusions and recommendations are provided. [ABSTRACT FROM PUBLISHER]

The objective of this paper is focused on the computer modelling and dynamic simulation of a coach with damaged wheel and the assessment of these negative effects on a track. The article is composed of two parts. Firstly, problems about the operation of rolling stocks with damaged wheels are described. There are also mentioned diagnostic systems installed on a track for detection and assessment their negative impacts on a track. The second part of the article is dedicated to computer modelling of a coach running on a railway track with the damaged wheel, in this case with the wheel-flat. For these purposes the virtual model of a coach were created. After simulations of its running there were performed analyses needed for the evaluation of its negative impacts on a railway track. [ABSTRACT FROM AUTHOR]