Grzegorz Kaczor

RAMS analysis of railway vehicles’ lifecycle

Abstract The presented paper investigates the issues concerned with the RAMS analysis with the reference to the railway means of transport. The RAMS analysis includes the quantitative and qualitative indicators of degree, that the system and its components will meet all the assumed functions preserving the requirements of the availability and safety. RAMS is a long-term process, resulted from the applied tools and techniques throughout the life cycle of railway means of transport. The overall guidelines related to the development of RAMS features are included in PN-EN 50126 Railway Applications - The Specification and Demonstration of Reliability, Availability, Maintainability and Safety (RAMS).

Scuffing wear of the tribological pairs under oscillatory motion

The surfaces of the friction pairs in oscillatory motion are exposed to the complex wear processes. Scuffing is a specific wear process, which comprises abrasive and adhesive wear. This paper presents the results of the preliminary scuffing tests, conducted on the T-05 test machine under oscillatory motion in the line contact. The results obtained from the tests confirmed the high probability of the scuffing occurrence under the assumed tests conditions. This is the basis for the planning of further research in this area. * Cracow University of Technology, al. Jana Pawła II 37, 31-864 Kraków, Poland, e-mails: wojtek@mech.pk.edu.pl, grzegorz.zajac@mech.pk.edu.pl, gkaczor@pk.edu.pl. T R I B O L O G I A 5-2016 32

Reliability and availability assessment of diesel locomotive Using fault tree analysis

The article presents an application of a method based on fault tree analysis and the Monte Carlo simulation in the assessment of reliability and availability of the rail means of transport. The primary target of the presented method is a cause and effect assessment of the occurrence of undesirable events, the determination of selected reliability indices and identification of the weakest components of rail vehicle that affect the downtime and technical availability most strongly. To illustrate the application of the presented method, the results of a project involving a 6Dg diesel locomotive, carried out in cooperation with the biggest Polish rail carrier, are shown. The assessment of availability and reliability was based on real operation data of a selected sample of seventy-five locomotives. Based on the collected data from the operation of the 6Dg locomotives, the times-to-failure and the times-to repair models were determined. A fault tree model of the locomotive was developed to assess the influence of the faults of the components on the reliability of the vehicle. A discrete simulation process allows to obtain a chosen characteristics and values of the selected measures, which – according to the authors – may be applied to assess the reliability and availability of the rail vehicles. Specialist software including Weibull++, BlockSim and MiniTab aided calculations were performed. The software includes and advanced solutions in the range of the reliability and availability simulations. The test results indicate that the proposed solution has a wide applicability potential