Residual stress measurement using the slitting method via a combination of eigenstrain, regularization and series truncation techniques

One of the challenges of measuring the residual stresses in metals and composites is the adverse effect of the noise and error on final results. The least squares and the Tikhonov regularization methods are the two available techniques for the noise reduction of the residual stress measurement in materials. In the present paper, the least squares method was developed for the residual stress measurement in metallic and laminated composites. Moreover, the application of the Tikhonov regularization method was extended for the eigenstrain based method and used for the measurement of residual stresses in laminated composites. The proposed methods were validated by performing experiments on an aluminum beam and a laminated composite plate using the slitting method. It was illustrated that the present methods diminished the uncertainty and sensitivity to noise of the final results successfully.