Rail vehicle impact analysis: A critique of the suitability of the rigid wall model and the assumption of symmetrical behaviour

Abstract

This paper studies the accuracy of rigid-wall (stonewall) and symmetric models in rail vehicle impact stability. The investigation is based on modelling results and theoretical analysis. The theoretical investigation consists of a mechanical description of the conservation of energy transformation and instability of train impact due to irregular structural collapse and loose coupling patterns. It is shown that an unstable response is a common consequence in vehicle impacts and the corresponding stiffness amongst cross-sections has a strong effect on collapse stability. The modelling investigation summarises impact simulations of a cab vehicle. This illustrates the pitfalls of the rigid-wall and symmetric models as follows: firstly, using a rigid wall in modelling could mask irregular deformations and lead to overestimated crashworthy performance behaviours; and secondly, symmetric impacts could lead to asymmetric deformations resulting in crucial irregular responses of rail vehicles being missed. This paper explores the irregular responses of rail vehicles in train collisions and highlights the relevant issues which might be overlooked when conventional static approaches are used in dynamic scenarios. It is anticipated that the paper will provide increased insight into impact mechanics of rail vehicles and promote a rethink about the influence of characteristic behaviours in dynamic responses resulting in a more accurate representation.

Keywords

Structural crashworthiness impact stability train collision rigid-wall model symmetric model vehicle design and modelling

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References

Kibble

TWB

Berkshire

. Classical mechanics, London, UK: Imperial College Press, 2005.

Scholes

Lewis

. Development of crashworthiness for railway vehicle structures. Proc IMechE 1993; 207(1): 1–16.

Cleon

. Resistance passive application au TGV 2N. Rev Gen Chemins Fer 1993; 65: 45–63.

Reizes

. Mechanics of vehicle collisions, Springfield, IL: Charles C Thomas, 1973.

Johnson

. Crashworthiness of vehicles, London, UK: Mechanical Engineering Publications, 1978.

Tong P. Rail vehicle structural crashworthiness. In: Jones N and Wierzbicki T (eds) Structural crashworthiness. Oxford, UK: Butterworth-Heinemann Ltd, 1983.

Jones

. Structural impact, Cambridge, UK: Cambridge University Press, 1989.

Abrate

. Impact on composite structures, Cambridge, UK: Cambridge University Press, 1998.

Sutton

. The development of rail vehicle crashworthiness. Proc IMechE, Part F, J Rail Rapid Transit 2001; 216(2): 97–108.

10.

Lewis

Rasaiah

Scholes

. Validation of measures to improve rail vehicle crashworthiness. Proc IMechE 1996; 210(2): 73–85.

11.

Cleon LM, Legait J and Villemin M. SNCF structural crashworthiness design strategy. In: Rail vehicle crashworthiness, Cambridge, MA, 24–26 June 1996. USA: US Department of Transportation, Federal Railroad Administration, Office of Research and Development, 1998.

12.

Wolter W. Impact of SAFETRAIN results on new European standard of crashworthiness of rail vehicles. In: The third international symposium on passive safety of rail vehicles, Berlin, Germany, 21–22 March 2002.

13.

Tyrell

. US rail equipment crashworthiness standards. Proc IMech E, Part F, J Rail Rapid Transit 2002; 216(2): 123–130.

14.

Tyrell

. Rail passenger equipment accidents and the evaluation of crashworthiness strategies. Proc IMech E, Part F, J Rail Rapid Transit 2002; 216(2): 131–147.

15.

Alghamdi

AAA

. Collapsible impact energy absorbers: an overview. Thin-Walled Struct 2001; 39: 189–213.

16.

Mayville R, Little AD, Johnson K and Tyrell D. The development of a rail passenger coach car crush zone. In: The third international symposium on passive safety of rail vehicles, Berlin, Germany, 21–22 March 2002.

17.

Karagiozova

Jones

. Dynamic elastic-plastic buckling of circular cylindrical shells under axial impact. Int J Solid Struct 2000; 37: 2005–2034.

18.

Avalle

Chiandussi

. Optimisation of a vehicle energy absorbing steel component with experimental validation. Int J Impact Engng 2007; 34: 843–858.

19.

Ahmad

Thambiratnam

Tan

ACC

. Dynamic energy absorption characteristics of foam-filled conical tubes under oblique impact loading. Int J Impact Engng 2010; 37: 475–488.

20.

Hallquist

. LS-DYNA theory manual, Livermore, CA, USA: Livermore Software Technology Corporation, 2006.