A new Approach in Residual Stresses Analysis by Speckle Interferometry
Abstract
The knowledge of residual stresses allows a reliable prediction of structure performances evolution, such as service life [1-3]. In this paper, we develop a new method for residual stresses determination combining Electronic Speckle Pattern Interferometry (ESPI) with the machining of a groove. The internal stress field is perturbed as the depth of the groove is increased incrementally. The structure finds a new equilibrium state generating displacements which are measured using ESPI. This method was tested on an aluminium alloy AU4G plate treated locally by an ultrasonic shot-peening. The investigation of the images obtained with the phase shifting technique and fringe patterns, makes it possible to analyze, simultaneously, the stress profile along two directions: along the depth of the structure, and along the groove direction.