EVALUATION OF RESIDUAL STRESS OF COPPER PIPE BY USING RAMAN SPECTROSCOPY

Abstract

In most cases, a straight pipe is used after complicated bending work in a mechanical system. In this work process, the plastic deformation of the pipe produces residual stress in the pipe. This residual stress significantly affects the behavior of pipe fracture. For this reason, residual stress must be evaluated. Measuring the residual stress of a U-shaped copper pipe is difficult with existing destructive and nondestructive measurement methods. In this paper, the residual stress of a U-shaped copper pipe (99.9% pure copper) was evaluated from the Raman shift by Raman spectroscopy and FEM analysis. Also, the results of the bending test by FEM analysis and experiments are compared. The analyzed results of Raman spectra had a similar tendency with the results of the FEM analysis in regard to the residual stress distributions in the U-shaped pipes. Also, the results of the bending tests were shown resemblance.