experimental and numerical study of through thickness residual stresses distribution in sheet metals produced by ecar

abstract: the equal channel angular rolling (ecar) is one of the severe plastic deformation processes, which can develop a shear deformation into a sheet metal. in this process, internal stresses are created due to the different strain levels experienced in different locations at the same time. the incremental hole drilling method is an effective technique for the evaluation of the through-thickness residual stress distribution in the metal sheets processed by the ecar. in this work, the residual stresses as the macro stresses have been considered by the help of the incremental method and fem for numerical calculation of the calibration coefficients. in addition, the fe simulation has been used to investigate the residual stress profile through the thickness. it was observed that the ecared sample was compressive at the top surface while it was in tension at the bottom surface and the stress profile was not uniform through the material thickness. a comparison between the hole drilling measurements and the fe simulation results showed a good agreement.