Predicting crack growth and risks of rail breaks due to wheel flat impacts in heavy haul operations

Abstract

The risk for rail breaks is investigated from mechanical and statistical points of view with particular focus on the influence of impact loads from flatted wheels. For a presumed rail head crack geometry and rail temperature, the stochastic relation between the crack position along the rail and the wheel flat impact position results in a risk of fracture. In addition to the analysis of the risk for final fracture, rail crack growth is also studied. In particular, the contribution of wheel flat impacts on crack growth rates is quantified.

The study takes the form of a dynamic load analysis that evaluates rail bending moments due to wheel flat impact. Then, a fracture mechanics analysis is employed to establish stress intensity factors for rail head cracks under bending and temperature loading. These analyses are then combined to give risks of rail breaks and to quantify crack growth rates for varying operational conditions.

Keywords

out-of-round wheels rail breaks rail cracks risk analysis fracture mechanics crack growth

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References

Smith

R. A.

‘The wheel – rail interface—some recent accidents’

Fatigue Fract. Eng. Mater. Struct. 2610 (2003): 901–907.

Ekberg

Kabo

‘Fatigue of railway wheels and rails under rolling contact and thermal loading – an overview’

Wear 2587–8 (2005): 1288–1300.

Nielsen

J. C. O.

Ringsberg

J. W.

Baeza

Influence of railway wheel flat impact on crack growth in rails. In Proceedings of the 8th International Heavy Haul Conference, Rio de Janeiro, Brazil, June 2005, pp. 789–797.

Fletcher

D. I.

Hyde

Kapoor

‘Growth of multiple rolling contact fatigue cracks driven by rail bending modelled using a boundary element technique’

Proc. Instn Mech. Engrs, Part F: J. Rail and Rapid Transit 218 F3 (2004): 243–253.

Jeong

D. Y.

Tang

Y. H.

Orringer

‘Damage tolerance analysis of detail fractures in rail’

Theor. Appl. Fract. Mech. 282 (1997): 109–115.

Nielsen

J. C. O.

Igeland

‘Vertical dynamic interaction between train and track – influence of wheel and track imperfections’

J. Sound Vibr. 1875 (1995): 825–839.

T. X.

Thompson

D. J.

‘A hybrid model for the noise generation due to railway wheel flats’

J. Sound Vibr. 2511 (2002): 115–139.

Ring Ed.

Säkerhetsordning BVF 900.3 (Swedish: Safety Regulations 1994): 236–237.

available from www.simulia.com.

10.

Martinez

Cross-sectional cracks in rails – evaluation of stress intensity factors Master's Thesis, 16 (Gothenburg, Sweden: Department of Applied Mechanics, Chalmers University of Technology 2006.

11.

Skyttebol

Josefson

B. L.

Ringsberg

J. W.

‘Fatigue crack growth in a welded rail under the influence of residual stresses’

Eng. Fract. Mech. 722 (2005): 271–285.

12.

Johansson

Out-of-round railway wheels – causes and consequences. An investigation including field tests, out-of-roundness measurements and numerical simulations (Gothenburg, Sweden: Department of Applied Mechanics, Chalmers University of Technology 2005. PhD Thesis, 16, Department of Applied Mechanics, Chalmers University of Technology, Gothenburg, Sweden, 2006.

13.

Nielsen

J. C. O.

Ekberg

Lundén

‘Influence of short-pitch wheel/rail corrugation on rolling contact fatigue of railway wheels’

Proc. IMechE, Part F: J. Rail and Rapid Transit 219 F3 (2005): 177–187.