An eigen-strain approach on the estimation of non-uniform residual stress distribution using incremental hole-drilling and slitting techniques

Abstract

Despite the advantages of incremental hole-drilling and slitting methods for measurement of residual stresses, there are also some limitations in their utilization. For example, decreasing of the measurement accuracy of strain gauges by increasing the hole depth in the incremental hole-drilling method, and necessity of having an assumption for distribution of the residual stress in form of a polynomial in the slitting method are the severe limitations of these two methods. Also, the calculation of the calibration coefficients of the slitting method is a complicated and time-consuming task. In the current study, by using the concept of the eigen-strain as the source of the residual stress, a new experimental-analytical method is developed for estimation of the residual stress using incremental the hole-drilling and slitting methods. To evaluate the accuracy of the proposed method, an aluminum sample with a specific distribution of a pre-induced residual stress has been studied. A comparison of the residual stress distribution obtained by the present method and the pre-induced residual stress in the specimen and theoretical prediction shows the accuracy of the new proposed method.