Numerical and experimental investigation of thickness effect on residual stress measurement

Abstract

This article studies the effect of thickness on residual stress measurements both numerically and experimentally. First, the released strain of aluminium specimens with different thicknesses subjected to incremental hole drilling is analysed using an efficient finite element model. From these results, the cumulative calibration coefficients and their variations as a function of plate thickness are determined. Then, the residual stress profile of a 1-mm-thick aluminium plate subjected to incremental hole drilling is investigated by in-plane three-directional moiré interferometry. A comparative study between the principle stress data calculated using the special calibration coefficients that match the thickness and the general ASTM calibration coefficients that are designed for thick plates is carried out. The analysis results demonstrate that the thickness significantly influenced the release strain. Moreover, the mismatch between the calibration coefficients and the thicknesses results in a deviation in the stress data of more than 10%, and the deviation increases with decreasing thickness.This paper is part of a Themed Issue on Measurement, modelling and mitigation of residual stress.