Optand, Sweden
Optand, Sweden

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Khan S.A.,Lulea University of Technology | Persson I.,AB DEsolver | Lundberg J.,Lulea University of Technology | Stenstrom C.,Lulea University of Technology
Wear | Year: 2017

Rolling contact fatigue (RCF) and wear, two major deterioration processes, limit the lifetime of rails. These deterioration processes are even more severe on the curves of tracks used by heavy haul trains. Because wear is a material removing process, it can suppress the formation of RCF (also known as surface initiated cracks). In railways, cracks have a higher risk of instigating a catastrophic failure than wear; hence, it is comparatively better to have wear than to have cracks. By controlling the top-of-rail friction, both of these deteriorating processes can be reduced to enhance the lifetime of rails. In order to achieve these possible advantages, the infrastructure manager of the Swedish railway is planning to implement a top-of-rail friction control technology on the iron ore line in northern Sweden wherein RCF is a major problem on the curves. The present study uses a damage index model in a multi-body simulation software and predicts the probability of RCF formation with suppressing effect of wear for different friction control values. The effect of friction control is simulated on curve radii ranging from 200 to 3000 m and axle loads ranging from 30 to 40 t at a constant train speed of 60 km/h. Findings show that on a very sharp circular curve, radius<300 m, RCF can be eliminated without friction control due to the high wear rate. On moderate curves, 300


Li M.,Swedish Transport Administration Trafikverket | Persson I.,AB DEsolver | Spannar J.,Swedish Transport Administration Trafikverket | Berg M.,KTH Royal Institute of Technology
Vehicle System Dynamics | Year: 2012

This paper studies the use of second-order derivatives of track irregularities (longitudinal level, LL) for assessing vertical track geometry quality. Both a single-degree-of-freedom and a three-DOF vehicle-track model are investigated in order to explain theoretically why from the aspect of vehicle-track dynamic interaction it is relevant to consider not only the amplitudes of LL but also their second-order derivatives (LL2). Simulation results are then presented to demonstrate that dynamic vertical track forces are more correlated with the second-order derivatives (LL2) than to the amplitudes (LL) themselves. A comparison of the power spectral density (PSD) spectra for typical track reveals that it is more convenient to use the PSD spectra for the second-order derivatives than for the amplitudes, as the curves for the second-order derivatives are flat within the short wavelength range. Finally, the practical use of derivatives within the maintenance management system in order to achieve improved assessment of track geometry quality is also discussed. © 2012 Copyright Taylor and Francis Group, LLC.


Petrov V.,KTH Royal Institute of Technology | Berg M.,KTH Royal Institute of Technology | Persson I.,AB DEsolver
Vehicle System Dynamics | Year: 2014

In certification of new rail vehicles with respect to running characteristics, a wide variety of operating conditions needs to be considered. However, in associated test runs the wheel-rail friction condition is difficult to handle because the friction coefficient needs to be fairly high and the friction is also generally hard to assess. This is an issue that has been studied in the European project DynoTRAIN and part of the results is presented in this paper. More specifically, an algorithm for estimating the wheel-rail friction coefficient at vehicle certification tests is proposed. Owing to lack of some measurement results, the algorithm here is evaluated in a simulation environment which is also an important step towards practical implementation. A quality measure of the friction estimate is suggested in terms of estimated wheel-rail spin and total creep. It is concluded that, tentatively, the total creep should exceed 0.006 and the spin should be less than 1.0 m-1 for the algorithm to give a good friction estimate. Sensitivity analysis is carried out to imitate measurement errors, but should be expanded in further work. © 2014 Taylor & Francis.


Spiryagin M.,Central Queensland University | Simson S.,Central Queensland University | Simson S.,Bradken Resources Ltd | Cole C.,Central Queensland University | Persson I.,AB DEsolver
Vehicle System Dynamics | Year: 2012

The design of mechatronic systems for rail vehicles requires the implementation of modern software tools. Nowadays, it is common to use co-simulation for the creation of mechatronic models. This approach is usually based on the combination of two types of software - multi-body simulation packages for mechanical models and tools for simulation of electric, control systems, etc. The existing commercial codes (SIMPACK, VI-RAIL, VAMPIRE, UM) provide different approaches for co-simulation; however, they have a lot in common. The one thing that makes them very similar is the use of Simulink for co-simulation. In this paper, we propose a description of the client interface in Simulink for co-simulation with Gensys. The evolution of the proposed approach has been performed by means of a simulation of a simplified traction control system for a hauling locomotive running on straight track conditions. © 2012 Taylor and Francis Group, LLC.


Spiryagin M.,Central Queensland University | Sun Y.Q.,Central Queensland University | Cole C.,Central Queensland University | Mcsweeney T.,Central Queensland University | And 2 more authors.
Vehicle System Dynamics | Year: 2013

The design of mechatronic systems of rail vehicles requires performing verification and validation in the real-time mode. One useful validation instrument is the application of software-in-the-loop, hardware-in-the-loop or processor-in-the-loop simulation approaches. All of these approaches require development of a real-time model of the physical system. In this paper, the investigation of the usage of the model of the locomotive's bogie test rig created in Gensys multibody software has been performed and the calculation time for each time step has been analysed. The verification of the possibility of the usage of such an approach for real-time simulation has been made by means of a simple data transferring process between Gensys and Simulink through the TCP/IP interface. The limitations and further development issues for the proposed approach have been discussed in this paper. © 2013 Copyright Taylor and Francis Group, LLC.


Spiryagin M.,Central Queensland University | Duan K.,Central Queensland University | Wu Q.,Central Queensland University | Cole C.,Central Queensland University | And 2 more authors.
CM 2015 - 10th International Conference on Contact Mechanics of Wheel / Rail Systems | Year: 2015

The calculation of temperatures in the contact zone at the wheel and rail interface is a very complex and important issue for multidisciplinary studies. The knowledge of temperature in the contact interface between two bodies and with the possible presence of a third body layer allows making informed judgments on processes in areas such as lubricant choice, wear estimation, life cycle prediction, etc. This paper is focused on the development of a temperature modelling methodology in Gensys multibody code which also presents its implementation for the study of temperatures at various common areas of contact (top of rail, gauge corner and gauge face contacts). Under normal operational practice, all these contact areas have different coefficients of friction which should be characterised as velocity and slip dependant variables. In order to show the workability of the developed methodology, numerical experiments for a heavy haul locomotive equipped with a simplified bogie traction control has been performed on curved track, where a locomotive has been operated under maximum traction forces and with longitudinal and lateral coupler forces attached in order to take into account train dynamics. For these experiments, both new and worn rail profiles have been used. Limitations of the proposed methodology as well as proposed future work and further improvements are discussed.


Persson I.,AB DEsolver | Nilsson R.,AB Storstockholms Lokaltrafik | Bik U.,AB Storstockholms Lokaltrafik | Lundgren M.,Interfleet Technology AB | Iwnicki S.,Manchester Metropolitan University
Vehicle System Dynamics | Year: 2010

In this paper, a genetic algorithm optimisation method has been used to develop an improved rail profile for Stockholm underground. An inverted penalty index based on a number of key performance parameters was generated as a fitness function and vehicle dynamics simulations were carried out with the multibody simulation package Gensys. The effectiveness of each profile produced by the genetic algorithm was assessed using the roulette wheel method. The method has been applied to the rail profile on the Stockholm underground, where problems with rolling contact fatigue on wheels and rails are currently managed by grinding. From a starting point of the original BV50 and the UIC60 rail profiles, an optimised rail profile with some shoulder relief has been produced. The optimised profile seems similar to measured rail profiles on the Stockholm underground network and although initial grinding is required, maintenance of the profile will probably not require further grinding. © 2010 Taylor & Francis.


Spiryagin M.,Central Queensland University | Wu Q.,Central Queensland University | Duan K.,Central Queensland University | Cole C.,Central Queensland University | And 2 more authors.
International Journal of Rail Transportation | Year: 2016

Calculation of the temperature in the contact zone at the wheel–rail interface is a very complex and important issue for multidisciplinary railway studies. The knowledge of temperature in the contact interface between two bodies, and with the possible presence of a third body interfacial layer, allows making informed judgments on processes in areas such as lubricant choice, wear estimation, life cycle prediction, etc. This paper focuses on development of a temperature modelling methodology in Gensys, and also presents its implementation for the study of temperatures at different contact points (top of rail, gauge corner, and gauge face contacts). In operational practice, all these mentioned contacts have different coefficients of friction which should be characterized as velocity and slip-dependent variables. To demonstrate the workability of the developed methodology, numerical experiments for a heavy haul locomotive equipped with a simplified bogie traction control system have been performed on curved track, where a locomotive has been operated under maximum traction forces and with longitudinal and lateral coupler forces attached in order to take into account train dynamics. Both new and worn rail profiles have been used. Limitations of the proposed methodology as well as proposed future work and further improvements are discussed. © 2016 Informa UK Limited, trading as Taylor & Francis Group

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