Abstract Train braking performance is important for the safety and reliability of railway systems. The availability of a tool that allows evaluating such performance on the basis of the main train features can be useful for train system designers to choose proper dimensions for and optimize kain’s subsystems. This paper presents a modular tool for the prediction of train braking performance, with a par- ticular attention to the accurate prediction of stopping distances. The tool takes into account different loading and operating conditions, in order to verify the safety require- ments prescribed by European technical specifications for interoperability of high-speed trains and the corresponding EN regulations. The numerical results given by the tool were verified and validated by comparison with experi- mental data, considering as benchmark case an Ansaldo EMU V250 train—a European high-speed train----currently developed for Belgium and Netherlands high-speed lines, on which technical information and experimental data directly recorded during the preliminary tests were avail- able. An accurate identification of the influence of the braking pad friction factor on braking performances allowed obtaining reliable results.69813

Keywords Braking performances - Friction behavior of braking pads -  Prediction tool

L. Pugi (II)   S. Papini   G. Vettori

Department of Industrial Engineering, University of Florence,

Via Santa Marta 3, 50139 Florence, Italy e-mail: luca.pugi1ë'unifi.it

M. Malvezzi

Department of Information Engineering and Mathematical Science, University of Siena, Via Roma 26, 53100 Siena, Italy

1 Introduction

Braking performance is a safety relevant issue in railway practice, impacting vehicle longitudinal dynamics, signal- ing, and traffic management, and its features and require- ments are important also for interoperability issues [1].

EN 14531 regulation [2] provides indications concern- ing preliminary calculation of braking performance, giving a general workflow that can be adapted to different vehicle categories:

• Freight wagons,

• Mass transit,

• Passenger coaches,

• Locomotives, and

• High-speed  trains.

The aim of the regulation [2] is to set a general method that should be shared among different industrial partners (industries, railway operators, safety assessors,  etc.).

The availability of software tools aimed to simulate the performance of braking system is useful to speed up and optimize the design process [3]. Braking performance eval- uation is also necessary to properly quantify the intervention curve of automatic train protection (ATP) systems [4, 5]. Some examples of kain brake system simulators are avail- able in the literature. In [6], David et at. presented a software tool for the evaluation of train stopping distance, developed in C language. In [7], the software TrainDy was presented; it was developed to reliably evaluate the longitudinal force distribution along a train during different operations. In [8], Kang described a hardware-in-the-loop (HIL) system for the braking system of the Korean high-speed train and analyzed the characteristics of the braking system via real-time sim- ulations. In [9], many interrelationships between various factors and types of braking techniques were analyzed.

Springer

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A simple but reliable tool able to simulate and predict the performances of braking system on the basis of a limited and often uncertain set of parameters could be useful and give interesting information to the designers on how to choose and optimize brake features, especially in the first phase of the design process of a new train.