Rail steel contact fatigue curves

Introduction. The problem of contact fatigue damage of rails has become especially urgent with the intensified railway freight load. An effective method of studying various damage factors is mathematical simulation of the dynamics of motion and accumulation of contact fatigue damage in the rail material. The damage accumulation simulation uses a curve of dependence of the number of wheel loading cycles or design rail section until contact fatigue failure on the value of the selected contact fatigue criterion. This curve could only be obtained in an experiment.

Materials and methods. The authors performed bench-scale contact fatigue testing of roller-shape rail steel specimens. The test rig of original design created a load of up to 4000 N on the rollers. The experimental data were processed using the finite element method. The problem of rolling the specimen and the counterbody was solved in the elastoplastic formulation.

Results. The authors studied the effects of the size and shape of the contact surfaces for the contact fatigue test specimens on the distribution of contact pressures. They designed and built a roller-on-roller contact fatigue test rig. The researchers tested rail steel specimens for contact fatigue. The results were processed using the finite element method with the plotting of contact fatigue curves of rail steel according to three criteria: combined, Dang Van criterion, amplitude value of maximum shear stress.

Discussion and conclusion. The developed methodological approach yielded contact fatigue curves of rail steel. The curves may be used in simulations of the accumulation of contact fatigue damage in the rail material under different axle loads, dynamic loads arising when the rolling stock moves in curves and straight track sections with different rolling profiles of wheels and rails.

1. Burkov D.N., Vaganova O.N. Actual problems of rail facilities. Railway Track and Facilities. 2022;(8):2-7. (In Russ.).

2. Zakharov S.M., Torskaya E.V. Approaches to modeling occurrence of rolling contact fatigue damages in rails. Russian Railway Science Journal. 2018;77(5):259-268. (In Russ.). https://doi.org/10.21780/2223-9731-2018-77-5-259-268.

3. Sakalo V.I., Sakalo A.V. Criteria for predicting the initiation of rolling contact fatigue damage in the railway wheels and rails. Russian Railway Science Journal. 2019;78(3):141-148. (In Russ.). https://doi.org/10.21780/2223-9731-2019-78-3-141-148.

4. Sakalo V.I., Sakalo A.V., Kossov V.S. Mechanics of contact interaction of wheel and rail. Moscow, Berlin: Direct-Media; 2021. 376 p. (In Russ.). EDN: https://www.elibrary.ru/jychir.

5. Akaoka J., Hirasawa K. Fatigue Phenomena under Rolling Contact Accompanied with Sliding. Bulletin of JSME. 1959;2(5):43-50. https://doi.org/10.1299/jsme1958.2.43.

6. Ishida M., Abe N. Experimental study on rolling contact fatigue from the aspect of residual stress. Wear. 1996;191:65-71.

7. Liu C.R., Choi Y. Rolling contact fatigue life model incorporating residual stress scatter. International Journal of Mechanical Sciences. 2008;50(12):1572-1577. https://doi.org/10.1016/j.ijmecsci.2008.10.008.

8. Borts A.I., Dolgikh L.V., Zagranichek K.L. Rail endurance testing. Railway Track and Facilities. 2013;(2):16-22. (In Russ.).

9. Clayton P., Su X. Surface initiated fatigue of pearlitic and bainitic steels under wear lubricated rolling/sliding contact. Wear. 1996;200:63-73.

10. Su X., Clayton P. Ratchetting strain experiments with a pearlitic steel under rolling/sliding contact. Wear. 1997;205:137-143.

11. Sakalo V.I., Sakalo A.V. Contact fatigue of rail and wheel steels. Laboratory tests. In: Fifth scientific and technical workshop “Computer simulation in railway transport: dynamics, strength, wear”, 4–6 October 2022, Bryansk. Bryansk, BGTU; 2022. p. 99–102. (In Russ.).

12. Ramalho A. Wear modelling in rail—wheel contact. Wear. 2015;330-331:524-532.

13. Zhao X., Wang Z., Wen Z., Wang H., Zeng D. The initiation of local rolling contact fatigue on railway wheels: An experimental study. International Journal of Fatigue. 2020;132:105354. https://doi.org/10.1016/j.ijfatigue.2019.105354.

14. Shkolnik L.M., Markov D.P., Proydak Y. S., Prokhorenko I.M., Tsurenko V. N., Miroshnichenko N. G., Bondarenko L.I. Increasing the endurance of railway wheels in operation by carbonitride hardening of steel. Russian Railway Science Journal. 1994;(6):40-44. (In Russ.).

15. Markov D.P. Improving the hardness of rolling stock wheels. Russian Railway Science Journal. 1995;(3):10-17. (In Russ.).

16. Dang Van K., Maitournam M.H. On some recent trends in modeling of contact fatigue and wear in rail. Wear. 2002;253(1-2):219-227. https://doi.org/10.1016/S0043-1648(02)00104-7.

17. Sakalo V., Sakalo A., Rodikov A., Tomashevskiy S. Computer modeling of processes of wear and accumulation of rolling contact fatigue damage in railway wheels using combined criterion. Wear. 2019;432-433: 102900. https://doi.org/10.1016/j.wear.2019.05.015.