Application of 2D finite element analysis to compare cracking behaviour in twin-disc tests and full scale wheel/rail experiments

摘要

This paper compares the stress and strain state simulated in a twin-disc test and a full scale wheel/rail experiment. The simulation is done by two-dimensional finite element models. The simulations regard the scaling factor between these experiments. This factor includes the contact patch size and the deformation depth. Same stresses and strains are calculated for both experiments considering this scale factor. For the investigation of cracks in these experiments, initiated short cracks or manually produced initial cracks are needed. The transferability of the crack growth predictions from twin-disc tests to the full scale wheel/rail experiments affords a scaling of the initial crack size to the size of the contact patches. Out of practical reasons usually the initial crack tips are located in both experiments in another depth as the scaling would afford and therefore, the tips are located in another zone of the plastic deformation. Very short cracks in the twin-disc tests are removed by wear or are influenced by the always existing surface roughness. It is shown that stresses and strains scale with the experiments but this will be not the case for wear and surface roughness. (C) 2015 Elsevier B.V. All rights reserved.