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

Document Type : Research Paper

Authors

1 Department of Mechanic, Faculty of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran And Quality Control of Maintenance Department, Esfahan Steel Co., Iran

2 Department of Mechanic, Faculty of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran

Abstract

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.

Keywords


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