Pattern of Residual Stress in Rail by FEM Analysis and Strain Gage Sectioning Technique

Final step of rail manufacturing is cold rolling straightening process and it has significant effects on mechanical properties, straightness, flatness and development of residual stresses. Measurement of residual stresses after straightening process is obligated by rail manufacturing standards. In the present investigation, an attempt has been made to evaluate residual stresses after straightening process by finite element method and strain gage sectioning technique. The straightening process has been simulated here using the FE package ABAQUS. All the input data were extracted from experimental tests according to rail manufacturing standard and homogenous and isotropic behavior of material were considered. Moreover, initial camber of the rail was measured after hot rolling and cooling process. Obtained results of numerical calculation has been validated by strain gage sectioning technique and compressive residual stresses in head and web and tension residual stress in foot of the rail has been observed. The roller arrangement used in this investigation could reduce the amount of residual stresses comparing with the previous results. Furthermore, straightness of the rail after straightening was satisfactory.