A study of multiple crack interaction at rolling contact fatigue loading of rails

Abstract

The objective of this paper is to investigate geometric and material parameters that affect the interaction of multiple pre-existing (initiated) cracks due to rolling contact fatigue (RCF) loading conditions. In particular, the behaviour of short cracks (head checks) in railway rail is studied. Parameters of interest are initial crack angle and spacing, distribution of initial crack lengths, width of the load/contact zone, and the material properties (in particular, the friction coefficient). Furthermore, the sensitivity of the finite element (FE)-mesh density is investigated. An open question of particular interest is the effect of crack interaction, e.g. shielding, on the prevailing crack spacing. In view of all uncertainties of the material model as well as the three-dimensional geometric complexity of the RCF problem, it is important to obtain a good understanding of the sensitivity of parameter changes. This is achieved in the presented investigation, although it is carried out using simplifying assumptions such as plane strain, linear elasticity, and Hertzian pressure distribution.