Residual Stress Analysis on Thin Metal Sheets Using the Incremental Hole Drilling Method - Fundamentals and Validation

The aim of the present work is to broaden the scope of application of the hole drilling method and to enable reliable residual stress measurements on thin metal sheets. In this context the focus is on characterization of residual stresses on brazed sheet metal constructions. In this specific case coarse grains and low sheet thickness are strong restrictions for standard residual stress measurement methods. However, in the current work it is shown that it is possible to extend the scope of application of the incremental hole drilling method to thin components. For this purpose, calibration coefficient matrices for sheets having thicknesses of 0.7mm, 1mm and 1.6mm have been calculated using finite element analysis. Furthermore, by measuring residual stresses of bent metal sheets, the determined coefficients and measurement procedure feasibility have been validated. Finally, the application of the incremental hole drilling method on an austenitic-ferritic brazed sheet metal construction is demonstrated.