Wear modelling in elasto-plastic wheel-rail contact problems

The paper is concerned with the development of the numerical procedure to solve the wheel-rail contact problem and the computation of the distribution of surface flash temperatures, stresses as well as the wear evolution due to friction. The two-dimensional wheel-rail contact problem between a rigid wheel and an elasto-plastic rail lying on a rigid foundation is considered. The contact phenomenon includes Coulomb friction, frictional heat generation as well as the wear of the contacting surfaces. The displacement and stress of the rail in contact are governed by the coupled elasto-plastic and heat conductive equations. The wear depth function appears as an internal variable in the non-penetration condition updating the gap between the worn surfaces of the bodies. Moreover the dissipated energy due to friction is calculated to evaluate the loss of rail material and to determine the shape of the contacting surfaces during the wear evolution process. This contact problem is solved numerically using the finite element method as well as the operator splitting approach. The plastic flow and friction inequality conditions are reformulated as equality conditions using the nonlinear complementarity functions. The distribution of surface temperatures and stresses as well as the evolution of the shape of the contact surfaces and the wear depth are reported and discussed

Assesment of The EMU and Track Condition Monitoring Results from Chosen Track Sections During Normal Operation

The paper contains analyses of the recorded acceleration signals obtained from the prototype of the rail vehicle suspension condition and track condition monitoring system. Primary and secondary suspension condition is assessed upon acceleration signals registered in measuring points located on bogie frames and vehicle body. The prototype is installed on electric multiple unit (EMU). Data was registered during normal operation of the vehicle on selected sections of one of the main rail lines in Poland. The aim of the analyses is to examine relation between proposed statistical parameters and normative parameters included in rail standards (UIC 518, EN 14363). The analyses were performed generally in cases of exceeding normative parameters values.The problem of assessment of results as well as monitoring system prototype are parts of research project 'MONIT - MONITORING OF TECHNICAL STATE OF CONSTRUCTION AND EVALUATION OF ITS LIFESPAN

Condition monitoring of railway track systems by using acceleration signals on wheelset axle-boxes

The aim of this paper is to demonstrate the possibilities of estimating the track condition using axle-boxes and car-bodies motions described by acceleration signals. In the paper, the results presented indicate the condition of tracks obtained from the preliminary investigation on the test track. Furthermore, the results from the supervised runs (on Polish Railway Lines) of Electric Multiple Unit (EMU-ED74) with the prototype of track quality monitoring system installed on-board are described. As Track Quality Indicator (TQI) algorithm, used in the mentioned prototype, a modified Karhunen–Loève transformation is used in preliminary preparation of acceleration signals. The transformation is used to extract the principal dynamics from measurement data. Obtained results are compared to other methods of evaluating the geometrical track quality, namely methods, which apply the synthetic coefficient Jsynth and five parameters of defectiveness W5. The results from the investigation showed that track condition estimation is possible with acceptable accuracy for in-service use and for defining cost-effective maintenance strategies. First published online 04 September 201

Secured Workstation to Process the Data of Different Classification Levels, Journal of Telecommunications and Information Technology, 2012, nr 3

The paper presents some of the results obtained within the ongoing project related with functional requirements and design models of secure workstation for special applications (SWSA). SWSA project is directed toward the combination of the existing hardware and software virtualization with cryptography and identification technologies to ensure the security of multilevel classified data by means of some formal methods. In the paper the requirements for SWSA, its hardware and software architecture, selected security solution for data processing and utilized approach to designing secure software are presented. The novel method for secure software design employs dedicated tools to verify the confidentiality and the integrity of data using Unified Modeling Language (UML) models. In general, the UML security models are embedded in and simulated with the system architecture models, thus the security problems in SWSA can be detected early during the software design. The application of UML topology models enables also to verify the fundamental requirement for MLS systems, namely the hardware isolation of subjects from different security domains

Simulation evaluation of the costs of adapting the low density traffic line to practical exploitation

AbstractThe issue of adapting the lines excluded for economic reasons from exploitation for a longer period of time by railway administration boards becomes in many countries, including Poland, a question of importance. Local governments, which own the areas where such railroads are located, are facing the problem of opening these lines but having in mind the improvement of life conditions of local communities. The actual task is grounded, however, in assessing the costs of opening – revitalizing of such a line. This article's aim is to present a simulation tool for assessing the cost of adapting a low density traffic line to practical exploitation

Assesment of The EMU and Track Condition Monitoring Results from Chosen Track Sections During Normal Operation

The paper contains analyses of the recorded acceleration signals obtained from the prototype of the rail vehicle suspension condition and track condition monitoring system. Primary and secondary suspension condition is assessed upon acceleration signals registered in measuring points located on bogie frames and vehicle body. The prototype is installed on electric multiple unit (EMU). Data was registered during normal operation of the vehicle on selected sections of one of the main rail lines in Poland. The aim of the analyses is to examine relation between proposed statistical parameters and normative parameters included in rail standards (UIC 518, EN 14363). The analyses were performed generally in cases of exceeding normative parameters values. The problem of assessment of results as well as monitoring system prototype are parts of research project 'MONIT - MONITORING OF TECHNICAL STATE OF CONSTRUCTION AND EVALUATION OF ITS LIFESPAN'

Asymmetric threats in terms of safety of railway systems

This article deals with the problem of new threats that appear in areas that have not been affected by them so far. The considerations concern asymmetric threats and the railway system. The analysis of this issue was carried out on the basis of general information on the problem of asymmetric threats and the knowledge of the railway system, its operation and identified threats that can be attributed to the characteristics of asymmetric threats. The aim of the article is to draw attention to new phenomena that are beginning to affect transport on a global basis, including rail transport

System monitorowania układu pojazd szynowy-tor jako kluczowy element zrównoważonego roz-woju transportu

Many definitions of “sustainable development” can be found in the literature. As some sources say the most frequently quoted definition is given in the Brundtland Report. It de-fines sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Sustainable devel-opment understood in that sense contains two key concepts: the concept of needs and the idea of limitations. The first one is truly important, however the second one seems to be more relevant here. The need to ensure the safety of today and the future generations is one of the needs to be assured in the framework of sustainable development. Giving the fact that the assurance may be achievable with the imposed restrictions – for example the impact on the environment – the issues related to transport arise in mind as some of rather “obvious” suggestions. Realisation of the need to ensure the safety concerns of the inte-grated transport system as such, but the need realisation should be related primarily to infra-structure and means of transport. Mode of transport which seems to be the least harm to the natural environment is railroad transport. Therefore the example of this type of execu-tion which is Rail Vehicle’s and Rail Track Monitoring System is considered in the paper. It will be the main subject matter of the paper.W literaturze przedmiotu znaleźć można wiele definicji zrównoważonego rozwoju, niemniej jednak najczęściej cytowaną definicją wydaje się być ta pochodząca z Raportu Brundtlanda. Według niej zrównoważony rozwój to taki w którym potrzeby obecnego pokolenia mogą być zaspokojone bez umniejszania szans przyszłych pokoleń na ich zaspokojenie. W tym kontek-ście zrównoważony rozwój zawiera dwa kluczowe pojęcia: koncepcje podstawowych potrzeb oraz idee ograniczonych możliwości. Mimo, że oba pojęcia mają nader istotne znaczenie, to jednak w kontekście niniejszego artykułu idea ograniczonych możliwości odgrywa ważną rolę. To właśnie konieczność zapewnienia bezpieczeństwa obecnym, ale również przyszłym poko-leniem ma niebagatelne znaczenie w kontekście zrównoważonego rozwoju. Zważywszy na fakt, że wspomniane bezpieczeństwo może być wypracowane poprzez nałożenie restrykcji m.in. dotyczących oddziaływania na środowisko, kwestie związane z transportem narastajądo rangi oczywistych sugestii. Bez wątpienia zapewnienie bezpieczeństwa związane jest z wdrożeniem systemu zintegrowanego transportu, tym niemniej zagwarantowanie bezpie-czeństwa powinno być związane przede wszystkim infrastrukturą oraz środkami transportu. W tym kontekście środkiem transportu, który wydaje się być najmniej szkodliwy dla środowi-ska naturalnego jest transport kolejowy, dlatego przykładem zapewnienia zasady bezpieczeń-stwa jest wprowadzenie Systemu monitorowania układu pojazd szynowy-tor. System ten bę-dzie głównym przedmiotem zainteresowania niniejszego opracowania

Simulational valuation of collisions for traction vehicle case

W artykule przedstawiono formalne wymagania w zakresie analizy zderzeń pojazdów szynowych oraz opis modelu symulacyjnego. Zaprezentowano wyniki badań symulacyjnych zderzeń lokomotywy przeprowadzonych wg normy PN-EN 15227. Praca prowadzona w ramach projektu badawczego nr N N509 0823 33 Modelowanie i symulacja w badaniach bezpieczeństwa technicznego pojazdów szynowych oraz projektu MONIT finansowanych ze środków MniSzW.The paper presents formal requirements for collision analysis of rail-road vehicles and description of the simulational model. The results of simulational collisions research according to EN-15227 are illustrated