A critical challenge in the aerospace, shipbuilding, energy industries, and broadly across mechanical engineering is the avoidance of fatigue failure that is often initiated by stress concentrators such as notches, slits, and other openings. An effective technique for improving fatigue resistance at concentrators, such as assembly holes, is a so-called ‘double-sided dimpling’ technique that uses elastoplastic indentation by spherical indenters to create local compressive residual stresses. This ought to allow optimizing fatigue resistance, provided the mechanisms of residual stress generation are duly quantified and controlled. Currently, however, these remain insufficiently understood. The present study aims to advance residual stress engineering through deepening the understanding and control of residual stress emergence under double-sided dimpling in an aluminum alloy 2024-T4 plate (Russian standard D16T). A multi-pronged approach was applied that combined several experimental techniques with finite element modeling (FEM) and analytical calculations. Experimentally, displacement fields were determined at the required accuracy and resolution by Digital Image Correlation using a standard smartphone camera. FEM model simulated double-sided dimpling-induced residual stress states with good agreement against experimental data by contact profilometry, X-ray diffraction, Digital Image Correlation, and Electronic Speckle-Pattern Interferometry. Furthermore, a novel analytical solution was proposed for the Lamé problem about thick-walled cylinder deformation under internal pressure in the elastoplastic formulation (autofrettage), followed by plug insertion. The presented approach serves as an example of Rational Experimental-Computational Correlation (RECC) that enables residual stress engineering through parameter optimization, offering a powerful tool to enhance the design against fatigue failure in engineering components.
Zorin et al. (2026) studied this question.