Experimental Study of Residual Stresses in Rail by Moire Interferometry

摘要

The residual stresses in rails produced by rolling cycles are studiedexperimentally by moire interferometry. The dissection technique is adopted for this investigation. The basic principle of the dissection technique is that the residual stress is released elastically by creating free boundaries when the specimen is cut into small pieces. In the study, instead of cutting small pieces, we cut the rail into thin slices first, and then cut grooves on the surface of the slice to produce many small grid elements with right angles. When the elements are small enough, it is assumed that the edges of the element are the stress free boundaries and thus relax the residual stress near the surface of the slice. The resulting deformation is measured by moire interferometry.