A numerical method for the simulation of freight train emergency braking operations based on the UIC braked weight percentage

Abstract

The present paper shows the development of a strategy for the calculation of the air brake forces of European freight trains. The model is built to upgrade the existing Politecnico di Torino longitudinal train dynamics (LTD) code LTDPoliTo, which was originally unable to account for air brake forces. The proposed model uses an empirical exponential function to calculate the air brake forces during the simulation, while the maximum normal force on the brake friction elements is calculated according to the indication of the vehicle braked weight percentage. Hence, the model does not require to simulate in detail the fluid dynamics in the brake pipe nor to precisely know the main parameters of the braking system mounted on each vehicle. The model parameters are tuned to minimize the difference between the braking distance computed by the LTDPoliTo code and the value prescribed by the UIC 544-1 leaflet in emergency braking operations. Simulations are run for different configurations of freight train compositions including a variable number of Shimmns wagons trailed by an E402B locomotive at the head of the train, as suggested in a reference literature paper. The results of the proposed method are in good agreement with the target braking distances calculated according to the international rules.

Keywords

Railway brake modelling / Emergency braking / UIC braking system / Braked weight / Longitudinal train dynamics

References

[1] Wu Q Spiryagin M Cole C. Longitudinal train dynamics: an overview. Veh Syst Dyn, 2016 54 12 1688-1714

[2] Cole C. Iwnicki S Spiryagin M Cole C McSweeney T. Longitudinal train dynamics and vehicle stability in train operations. Handbook of railway vehicle dynamics, 2020 Boca Raton CRC Press 457-519

[3] Cole C (1998) Improvements to wagon connection modelling for longitudinal train simulation. Presented at CORE 1998: engineering innovation for a competitive edge: conference on railway engineering, Yeppoon, Queensland, Australia

[4] Massa A Stronati L Aboubakr AK Shabana AA Bosso N. Numerical study of the noninertial systems: application to train coupler systems. Nonlinear Dyn, 2012 68 1 215-233

[5] Wu Q Cole C Luo S Spiryagin M. A review of dynamics modelling of friction draft gear. Veh Syst Dyn, 2014 52 6 733-758

[6] Bosso N, Magelli M, Zampieri N (2020) Long train dynamic simulation by means of a new in-house code. WIT Trans Built Environ 199:249–259

[7] Bosso N Magelli M Zampieri N. Development and validation of a new code for longitudinal train dynamics simulation. Proc Inst Mech Eng Part F J Rail Rapid Transit, 2020 235 3 286-299

[8] Bosso N Magelli M Zampieri N. Validation of a new longitudinal train dynamics code for time domain simulations and modal analyses. Int J Transp Dev Integr, 2021 5 1 41-56

[9] Spiryagin M Wu Q Cole C. International benchmarking of longitudinal train dynamics simulators: benchmarking questions. Veh Syst Dyn, 2017 55 4 450-463

[10] Wu Q Spiryagin M Cole C Chang C Guo G Sakalo A . International benchmarking of longitudinal train dynamics simulators: results. Veh Syst Dyn, 2018 56 3 343-365

[11] Wu Q Cole C Spiryagin M . Freight train air brake models. Int J Rail Transp, 2021

[12] Cantone L Crescentini E Verzicco R Vullo V. A numerical model for the analysis of unsteady train braking and releasing manoeuvres. Proc Inst Mech Eng Part F J Rail Rapid Transit, 2009 223 3 305-317

[13] Cantone L. TrainDy: the new union internationale des chemins de fer software for freight train interoperability. Proc Inst Mech Eng Part F J Rail Rapid Transit, 2010 225 1 57-70

[14] Wu Q Cole C. Computing schemes for longitudinal train dynamics: sequential, parallel and hybrid. J Comput Nonlinear Dyn, 2015 10 6 064502

[15] Wu Q Cole C Spiryagin M Wang Y Ma W Wei C. Railway air brake model and parallel computing scheme. J Comput Nonlinear Dyn, 2017 12 5 051017

[16] Belforte P Cheli F Diana G Melzi S. Numerical and experimental approach for the evaluation of severe longitudinal dynamics of heavy freight trains. Veh Syst Dyn, 2008 46 sup1 937-955

[17] UIC (2004) 544-1: brakes—braking power

[18] Di Gialleonardo E Melzi S Trevisi D. Freight trains for intermodal transportation: optimisation of payload distribution for reducing longitudinal coupling forces. Veh Syst Dyn, 2022

[19] Bosso N Magelli M Rossi Bartoli L Zampieri N. The influence of resistant force equations and coupling system on long train dynamics simulations. Proc Inst Mech Eng Part F J Rail Rapid Transit, 2022 236 1 35-47

[20] Zhang Z Li G Chu G Zu H Kennedy D. Compressed stability analysis of the coupler and buffer system of heavy-haul locomotives. Veh Syst Dyn, 2015 53 6 833-855

[21] UIC (2006) 540: brakes—air brakes for freight trains and passenger trains

[22] Bosso N Gugliotta A Magelli M Oresta IF Zampieri N. Study of wheel-rail adhesion during braking maneuvers. Procedia Struct Integr, 2019 24 680-691

[23] Pugi L Rindi A Ercole AG Palazzolo A Auciello J Fioravanti D Ignesti M. Preliminary studies concerning the application of different braking arrangements on Italian freight trains. Veh Syst Dyn, 2011 49 8 1339-1365

[24] Pugi L Malvezzi M Allotta B Banchi L Presciani P. A parametric library for the simulation of a Union Internationale des Chemins de Fer (UIC) pneumatic braking system. Proc Inst Mech Eng Part F J Rail Rapid Transit, 2004 218 2 117-132