Papers by Caterina Ariaudo
The 5th Joint International Conference on Multibody System Dynamics, Jun 1, 2018
International Journal of Railway Technology, 2018
Lecture Notes in Mechanical Engineering, 2020
Dynamic loads exchanged between the rolling stock and the operated track are intrinsic to the rai... more Dynamic loads exchanged between the rolling stock and the operated track are intrinsic to the railway operation environment. The purpose of the authors is to trace a path towards a realistic definition of a load mission profile for the structural fatigue dimensioning of the vehicle components. In former works, the methodology to study how the varying characteristics of vehicle components, in normal and degraded conditions, can impact on the vehicle/track interaction loads and on the track damage, was widely dealt with. In this paper, the same methodology is applied to study the impact of modified track conditions on the vehicle/track interaction loads. The focus of this paper is therefore on the characterization of the track and its maintenance status, necessary to simulate the real loads experienced by the vehicle and by the track itself. The aim is to highlight what “indexes of health of the track” weight more on the dynamic loads exchanged between the vehicle and the track, and shall therefore be kept under control, to minimize safety risks and operational costs. The assessment criteria are defined according to the EN14363 regulation.
Proceedings of the 24th Symposium of the International Association for Vehicle System Dynamics (IAVSD 2015), Graz, Austria, 17-21 August 2015, 2016
Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance
Proceedings of the Second International Conference on Railway Technology: Research, Development and Maintenance
Proceedings of the Second International Conference on Railway Technology: Research, Development and Maintenance
IEEE/ASME/ASCE 2008 Joint Rail Conference, 2008
One of the key-elements of train design is the wheelset lifetime, which is strongly dependent on ... more One of the key-elements of train design is the wheelset lifetime, which is strongly dependent on the levels of wheel wear. In order to reduce costs and increase safety, wheel wear needs to be predicted with increasing precision. In the past few years specific tools have been introduced to combine the predicted dynamic data from multi-body models, with the analytical computation of the wheel-rail contact parameters, to achieve an improved wear prediction. The aim of the present work is to consider the different methodologies for wear prediction and to create a wear prediction tool which is based on available railway dynamics codes enhanced by improved rolling contact analysis, combined with recent research on wear.
STLE/ASME 2008 International Joint Tribology Conference, 2008
Twin disc tests are commonly used to study wear in railway materials. In this work the implementa... more Twin disc tests are commonly used to study wear in railway materials. In this work the implementation of a numerical model of the twin disc arrangement is given, which reproduces the distribution of tangential forces over the contact patch between the two discs. Wear is subsequently calculated by relating the forces and creepage between the two discs using three different wear functions found in the literature. The resulting wear rates are compared with experimental data found at the University of Sheffield for discs made of common railway wheel and rail steels. This allows a comparison and assessment of the validity of the different wear algorithms considered.
Multibody System Dynamics, 2010
In the past, the reprofiling intervals of railway vehicle steel wheels have been scheduled accord... more In the past, the reprofiling intervals of railway vehicle steel wheels have been scheduled according to designers' experience. Today, more reliable and accurate tools in predicting wheel wear evolution and wheelset lifetime can be used in order to achieve economical and safety benefits. In this work, a computational tool that is able to predict the evolution of the wheel profiles for a given railway system, as a function of the distance run, is presented. The strategy adopted consists of using a commercial multibody software to study the railway dynamic problem and a purpose-built code for managing its pre and post-processing data in order to compute the wear. The tool is applied here to realistic operation scenarios in order to assess the effect of some service conditions on the wheel wear progression.
International Journal of Railway Technology, 2014
The wheel wear prediction is a key-topic in the field of railway research as it has big impact on... more The wheel wear prediction is a key-topic in the field of railway research as it has big impact on economical and safety aspects of trainset design, operation and maintenance. The aim of this work was to implement a flexible and pre-dictive railway wheel wear tool that, starting from a specific vehicle mission, provides the wheel profile evolution as a function of the distance run. The we-ar estimation tool consists of the use of a sequence of pre and post-processing packages, in which the methodologies now presented are implemented, inter-faced with a commercial multibody software that is used to study the railway dynamics. The computational tool is applied here to several simulation sce-narios. The purpose is to demonstrate its capabilities on wear prediction by evaluating the influence of trainset design and of track layout on the wheel wear growth. Special attention is also given to study how the wear evolution is affected by the friction conditions between the wheel and rail.
International Journal of Railway Technology, 2013
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit
The optimisation of the dynamic behaviour of an electric railway vehicle cannot disregard the eff... more The optimisation of the dynamic behaviour of an electric railway vehicle cannot disregard the effects of the driveline in the traction and braking phases when the electrical and mechanical systems mutually exchange excitations and loads. To this end, complex and reliable models for the simulation of the whole chain, from the power collector to the wheel–rail contact including control algorithms, are necessary. Using detailed and validated standalone models of the electrical and mechanical systems, developed in Simulink and in SIMPACK, respectively, the authors have studied, tuned and validated a closed loop simulation methodology. While the standalone simulation models for different rolling stock solutions have been dealt in other papers and conferences, in this paper, the readers will find a description of the steps necessary to obtain realistic co-simulations based on Simulink and SIMPACK models operating in a closed loop and the definition of an opportune interface that guarantee...
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science
The rail infrastructure and the track components are expensive assets with long life spans and hi... more The rail infrastructure and the track components are expensive assets with long life spans and high maintenance costs. The cost efficiency, performance and punctuality of train operations heavily depend on the track conditions. Ideally, the railway track would be completely smooth providing continuous support to the rolling stock running on it. In practice, however, the infrastructure cannot be installed without irregularities. These defects will increase over time due to the service loads imposed by the railway vehicles. The aim of this work is to use advanced computational tools to predict how the vehicles will respond to changing levels of track defects. For this purpose, the track and its maintenance conditions are characterized in realistic operation scenarios and modelled with detail in order to enable studying the interaction loads that are imposed to the vehicles by the track conditions. The presented methodology enables to identify the track health indexes that have higher ...
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science
To improve the efficiency and competitiveness of railway transport, passenger and freight trains ... more To improve the efficiency and competitiveness of railway transport, passenger and freight trains should travel faster and have increased payload, without losing the necessary levels of running safety and ride comfort, as well as assuring low aggressiveness on track and minimising the life cycle costs. Hence, the manufacturer’s challenge consists of improving the dynamic performance of the railway vehicles and reducing the loads on the track as well as on the rolling stock components. These objectives can be achieved through optimizing the design of the vehicle, while taking into consideration that the characteristics of the vehicle and of the track may change over time and space, and that they depend on the maintenance conditions of the vehicle and of the infrastructure. This work proposes a computational methodology to study how the varying vehicle component characteristics, on normal and degraded conditions, impact on the vehicle/track interaction loads and on the track damage. Th...
Uploads
Papers by Caterina Ariaudo