Rolling contact fatigue assessment of repair rail welds

Paper i proceeding, 2018

A repair welding procedure is numerically simulated. To validate the numerical model, analyses of the temperature evolution are compared to full-scale test results. Further simulations are then carried out to evaluate the residual stress formation during welding and how the residual stress field is influenced by subsequent wheel passages. The influence of residual stresses from welding and the subsequent residual stress redistribution during operations on the risk of rolling contact fatigue (RCF) is discussed and analyzed. It is found that high tensile stresses are formed during welding, however these shake down substantially during subsequent operations. The influence on RCF is found to be moderate on the surface and somewhat more severe in a layer at the bottom of the repair weld. In addition to residual stresses, there is also a risk that welding introduces material defects and alters material properties. The influence of such phenomena on RCF are discussed.