Crack path modelling in railway wheel under rolling contact fatigue

Michal Kotoul

Abstract


Acomputationalmodel of crack path for two-dimensional primary crack situated in a railway wheel rim is designed. The railway wheel rim is placed on thewheel disc of railway wheel with interference fit. Crack behaviour is analysed in the case of rectilinear ride of a train under rolling contact fatigue. Plank and Kuhn criterion is used to decide whether crack will either kink and follow mode I controlled (tensile mode) path, or it will propagate coplanar mode II controlled (shear mode). If mode I controlled crack growth is more probable then a direction of crack propagation is predicted using the maximum tensile stress range criterion. In this way a relationship between stress intensity factors and crack geometry is obtained. For comparison, crack behaviour in a solid railway wheel which is not subjected to pre-stress loading is also analysed. In the latter case the contact forces in the wheel-rail contact are considered to have i) only normal part ii) both the normal part and tangential part.


Keywords


rolling contact fatigue crack; non-proportional loading; mixed mode; railway wheel; FEM

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