Preliminary studies concerning the application of different braking arrangements on Italian freight trains

Pugi, Luca; Rindi, Andrea; Ercole, Andrea Giuseppe; Palazzolo, A; Auciello, Jury; Fioravanti, Duccio; Ignesti, Mirko

doi:10.1080/00423114.2010.505291

Cited by 54 publications

(42 citation statements)

References 6 publications

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“…Belforte et al [29] established a 3-D vehicle dynamic model subjected to the coupler forces under the braking conditions, and then discussed the vehicle running safety in the switch sections. For the same research purpose, Pugi et al [30] put forward a mixed train model which consisted of the single-DOF wagons and the multi-DOF wagons. Recently, developing a complete train model has become the research tendency.…”

Section: Introductionmentioning

confidence: 99%

Establishment and verification of three-dimensional dynamic model for heavy-haul train–track coupled system

Liu

Zhai

Wang

2016

Vehicle System Dynamics

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For the long heavy-haul train, the basic principles of the intervehicle interaction and train-track dynamic interaction are analysed firstly. Based on the theories of train longitudinal dynamics and vehicle-track coupled dynamics, a three-dimensional (3-D) dynamic model of the heavy-haul train-track coupled system is established through a modularised method. Specifically, this model includes the subsystems such as the train control, the vehicle, the wheel-rail relation and the line geometries. And for the calculation of the wheel-rail interaction force under the driving or braking conditions, the large creep phenomenon that may occur within the wheel-rail contact patch is considered. For the coupler and draft gear system, the coupler forces in three directions and the coupler lateral tilt angles in curves are calculated. Then, according to the characteristics of the long heavy-haul train, an efficient solving method is developed to improve the computational efficiency for such a large system. Some basic principles which should be followed in order to meet the requirement of calculation accuracy are determined. Finally, the 3-D train-track coupled model is verified by comparing the calculated results with the running test results. It is indicated that the proposed dynamic model could simulate the dynamic performance of the heavy-haul train well. ARTICLE HISTORY

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Section: Introductionmentioning

confidence: 99%

Establishment and verification of three-dimensional dynamic model for heavy-haul train–track coupled system

Liu

Zhai

Wang

2016

Vehicle System Dynamics

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“…Enthalpy exchanges introduced by the hydraulic actuators have to be evaluated for the calculation of the proper enthalpy flow; indeed, the specific enthalpy h delivered in the outlet section has to be coherently recomputed taking into account the exchanged mechanical work calculated in equation (3). Even considering the delivered hydraulic power W h and the efficiency of the pump (, ), it is possible to compute the mechanical power W m and the required torque T m .…”

Section: R and Ri Components: Sketches And Equationsmentioning

confidence: 99%

“…The general approach followed in literature, 4,5 for a mono-dimensional flow, is described in terms of mass conservation, momentum and enthalpy balances based on the following equations (1) to (3) (where symbols and conventions are briefly described in Table 1). …”

Section: Tth Lib Descriptionmentioning

confidence: 99%

“…[1][2][3] Authors, during the collaboration between the University of Florence (in particular the Mechatronics and Dynamic Modelling Lab) and the industrial partner GE Oil & Gas Nuovo Pignone (Florence, Italy), have implemented a tool (briefly named 'thermal hydraulic library (TTH Lib)') that represents an innovative trade off among different features proposed by the known commercial software and the internal specifications of GE NP procedures.…”

Section: Introductionmentioning

confidence: 99%

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A preliminary study of thermal hydraulic models for virtual hazard and operability analysis and model-based design of rotating machine packages

Conti

Presti²,

Pugi

et al. 2013

Proceedings of the Institution of Mechanical Engineers, Part E:

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Hazard and operability analysis is a decisive factor to evaluate safety and reliability of plants considering the propagated effects due to consecutive failures of known critical components. A good design and analysis practice increases the robustness of the considered system in different operating conditions; however, in the plant design process, the use of a model-based design approach is fundamental to increase speed, efficiency and reliability. In this work, a tool for the 1-D simulation of thermal hydraulic plants is presented and applied to the analysis of critical system for compressor and gas turbine units, e.g. the lubrication circuits. Different from known commercial products, the proposed tool is implemented to work in cooperation with PidXP TM (the GE Nuovo Pignone P&ID definition tool), and it is optimized for fixed step solvers in order to easily include the rotating machine control logics within the simulation environment (essential prerequisite for hazard and operability evaluations). All the above makes it suitable for the fast prototyping of real time code. Moreover, the proposed tool represents a general tool in the model-based approach, and it can be used as a Simulink TM library of components that have been optimized and specifically designed in order to make easier the automatic generation of simulation models from P&Id schemes and technical documentation, reducing errors associated to data transcription and operator misbehaviour. In this work, proposed approach and test bench on experimental data for validation purposes are shown.

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“…His circular variable method was acknowledged as a low-cost approach to simulating train system dynamics. Pugi et al [5] focused on the relationship between coupler force and relative load reduction. His work was performed using multi-body dynamics and pneumatics methods.…”

Section: Introductionmentioning

confidence: 99%

Assessment of the curving performance of heavy haul trains under braking conditions

et al. 2015

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To study the curving performance of trains, 1D and 3D dynamic models of trains were built using numerical methods. The 1D model was composed of 210 simple wagons, each allowed only longitudinal motion; whereas the 3D model included three complicated wagons for which longitudinal, lateral, and vertical degrees of freedom were considered. Combined with the calculated results from the 1D model under braking conditions, the behavior of draft gears and brake shoes were added to the 3D model. The assessment of the curving performance of trains was focused on making comparisons between idling and braking conditions. The results indicated the following: when a train brakes on a curved track, the wheel-rail lateral force and derailment factor are greater than under idling conditions. Because the yawing movement of the wheelset is limited by brake shoes, the zone of wheel contact along the wheel tread is wider than under idling conditions. Furthermore, as the curvature becomes tighter, the traction ratio shows a nonlinear increasing trend, whether under idling or braking conditions. By increasing the brake shoe pressure, train steering becomes more difficult.

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Preliminary studies concerning the application of different braking arrangements on Italian freight trains

Cited by 54 publications

References 6 publications

Establishment and verification of three-dimensional dynamic model for heavy-haul train–track coupled system

Establishment and verification of three-dimensional dynamic model for heavy-haul train–track coupled system

A preliminary study of thermal hydraulic models for virtual hazard and operability analysis and model-based design of rotating machine packages

Assessment of the curving performance of heavy haul trains under braking conditions

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