2026-05-31T01:45:41Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/82982024-01-12T01:05:32Zcom_10259_6214com_10259_5086com_10259_2604col_10259_6215

Calaf Chica, José Marín, Marta María Rubio, Eva María Teti, Roberto Segreto, Tiziana 2024-01-11T11:08:01Z 2024-01-11T11:08:01Z 2019-12 http://hdl.handle.net/10259/8298 10.3390/ma12244105 1996-1944 Cold expansion technology is a cold-forming process widely used in aeronautics to extend the fatigue life of riveted and bolted holes. During this process, an oversized mandrel is pushed through the hole in order to yield it and generate compressive residual stresses contributing to the fatigue life extension of the hole. In this paper, a parametric analysis of the mandrel geometrical data (inlet angle straight zone length and diametric interference) and their influence on the residual stresses was carried out using a finite element method (FEM). The obtained results were compared with the conclusions presented in a previous parametric FEM analysis on the influence of the swage geometry in a swaging cold-forming process of gun barrels. This process could be considered, in a simplified way, as a scale-up of the cold expansion process of small holes, and this investigation demonstrated the influence of the diameter ratio (K) on the relation between the mandrel or swage geometry and the residual stresses obtained after the cold-forming process. This work has been funding, in part, by grants from Industrial Engineering School-UNED (REF2019-ICF05 and REF2019-ICF08). application/pdf eng MDPI Materials. 2019, V. 12, n. 24, 4105 https://doi.org/10.3390/ma12244105 Atribución 4.0 Internacional http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Cold expansion Mandrel Cold-forming Swaging Ingeniería civil Resistencia de materiales Civil engineering Strength of materials Parametric Analysis of the Mandrel Geometrical Data in a Cold Expansion Process of Small Holes Drilled in Thick Plates info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Materials 12 24