Experimental study of three-dimensional residual stresses in rails by moiré interferometry and dissecting methods

Residual stresses in rails produced by rolling cycles are studied by a destructive testing procedure. Thin slices of rails are cut and small grid elements are made by cutting slots onto the surface of the slice. Residual stresses are believed to be released near the surface of the slice when those grid elements have right angles and are sufficiently small. The resulting deformation produced by the stress relief is measured by moiré interferometry. On assuming all strain components be constant along the longitudinal axis of the rail and this axis is one principal direction, three-dimensional strain and stress components are solved.