Simplified Model of Elastic-Plastic Wheel/Rail Interactions
The results of numerical calculations, presented in the paper , demonstrate a significant role of plastic yield in the process of formation of the rail corrugations. Below, certain analytical solutions for a simplified model of wheel/rail interaction process are given. At first, normal and tangent loads of rails, assumed on the basis of the results presented in the paper , are analyzed. The corresponding elastic stress field is given in explicit form. Next, a complete solution for a thin, plastic surface layer of rail is proposed. The simple analytical expressions enable us to calculate the changes of the limit shear stress and residual stresses under the wheel/rail contact surface after successive passings of a wheel. Two cases are considered: a load moving with constant amplitude and a load moving with cyclically changing amplitude. Two important facts are proved. The first one – that the limit shear stress (K) and the longitudinal residual stress (R) under the running surface of rail converge to asymptotic values. The second one – that the final location of K peaks and R valleys corresponds to the positions of rail corrugations.
R. BOGACZ, On residual stresses in rails and wheel/rail interaction; in Residual Stresses in Rails, vol. 2, Kluwer Academic Publishers, 1992.
M. BRZOZOWSKI, R. BOGACZ and K. POPP, Zur Reibungsmodellierung beim Rollkontakt, ZAMM, 70, 6, T 678 - T 679, 1990.
K.L. JOHNSON, Contact mechanics, Cambridge University Press, 1985.
R. MAIR and R. GROENHOUT, The growth of transverse fatigue defects in head of railway rails, [in:] Rail Research Papers; Compendium of BHP Steel International Group, vol. 1, Melbourne 1980.
W. GAMBIN, A. NAKONIECZNY, K. SKALSKI, Original and stain induced plastic anisotropy in metal surface layers, J. Theor. Appl. Mech., 31, 4, 1993.
Copyright © 2014 by Institute of Fundamental Technological Research
Polish Academy of Sciences, Warsaw, Poland