Reconstruction of Residual Hoop Stress in Railroad Car Wheels Based on Saw Cut Measurements

Railroad car wheels develop residual stresses both in their manufacture and once in service. Knowledge of residual stress distribution and its variation over time is necessary for the prediction of wheel service life and possible catastrophic failure. It is vital for the safety of railway transportation. Although a theoretical solution is possible, it remains complex. Alternatively, the solution may be also obtained by using the experimental measurements assisted by the theory of mechanics. An approach known as "physically based enhancement of experimental data" formulated, subsequently developed and tested provides the most accurate results for the reconstruction of acquired residual hoop stress component in railroad car wheels. The paper presents the formulation, solution approach and results of the analysis performed on experimental data registered in investigations of the passenger and freight wheels during their saw-cutting process. The task has been formulated and solved as a nonlinear constrained optimization analysis. The discussion on the results precision has been included.