Print Email Facebook Twitter Residual stress measurements and model validation of single and double pulse resistance spot welded advanced high strength steel Title Residual stress measurements and model validation of single and double pulse resistance spot welded advanced high strength steel Author Eftekharimilani, P. (TU Delft (OLD) MSE-5) Gao, H. (TU Delft (OLD) MSE-1; TU Delft (OLD) MSE-5; Tata Steel, 1970 CA IJmuiden, the Netherlands) Huizenga, R.M. (TU Delft (OLD) MSE-1) van der Aa, EM (Tata Steel) Amirthalingam, M. (TU Delft (OLD) MSE-5; Indian Institute of Technology Madras) Richardson, I.M. (TU Delft (OLD) MSE-5) Hermans, M.J.M. (TU Delft (OLD) MSE-5) Contributor Sommitsch, Christof (editor) Enzinger, Norbert (editor) Mayr, Peter (editor) Date 2018 Abstract Advanced high strength steels (AHSS) are increasingly used in automotive industry; thousands of resistance spot welds are applied to car body-in-white. High alloying levels of AHSS result in lower weldability. Residual stresses play an essential role on the formation of defects and the mechanical performance of the weld. An electrical-thermal-metallurgical-mechanical finite element model was constructed to simulate the temperature and stress distribution during single and double pulse resistance spot welding. The models are validated by ex-situ synchrotron X-ray diffraction stress measurements. In this paper, single pulse and double pulse resistance spot welds were made on 1.3 mm thin sheets of a 3rd generation AHSS. Depth resolved stress measurements in two orthogonal directions were carried out using high-resolution powder diffraction at beamline ID22 of the European Synchrotron Research Facility. A monochromic 70 keV X-ray was used to record the d-spacing of (200) bcc planes in transmission mode. The strains were calculated from the shift in the d-spacing of the planes. The stresses were calculated by the biaxial Hook’s law. The numerical and experimental results show that the residual stresses in the weld nugget zone and the heat affected zone of the welds are tensile in nature, whereas the base material experiences compressive stresses. Lower residual stresses at the weld nugget and HAZ were obtained by applying a second current pulse. The simulated results show a good agreement with the residual stresses measured. This study provides a better understanding of the stress distribution in resistance spot welds and allows prediction of stresses as a result of welding conditions applied. Subject Solidification CrackingHot CrackingSteelLaser WeldingAutomotiveAdvanced high strength steels (AHSS) To reference this document use: http://resolver.tudelft.nl/uuid:986d8203-6d08-406c-a982-585dc05653ac DOI https://doi.org/10.3217/978-3-85125-615-4-22 Publisher Verlag der Technischen Universitat Graz ISBN 978-3-85125-615-4 Source Mathematical Modelling of Weld Phenomena 12, 12 Event 12th International Seminar Numerical Analysis of Weldability, 2018-09-23 → 2018-09-26, Graz, Austria Part of collection Institutional Repository Document type conference paper Rights © 2018 P. Eftekharimilani, H. Gao, R.M. Huizenga, EM van der Aa, M. Amirthalingam, I.M. Richardson, M.J.M. Hermans Files PDF eftekharimilani_residual_stress.pdf 1.08 MB Close viewer /islandora/object/uuid:986d8203-6d08-406c-a982-585dc05653ac/datastream/OBJ/view