Residual stress measurements and model validation of single and double pulse resistance spot welded advanced high strength steel

Parisa Eftekharimilani, He Gao, Richard Huizenga, EM van der Aa, Murugaiyan Amirthalingam, Ian Richardson, Marcel Hermans

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

51 Downloads (Pure)

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.
Original languageEnglish
Title of host publicationMathematical Modelling of Weld Phenomena 12
EditorsChristof Sommitsch, Norbert Enzinger, Peter Mayr
PublisherVerlag der Technischen Universitat Graz
Pages401-415
Volume12
ISBN (Electronic)978-3-85125-616-1
ISBN (Print)978-3-85125-615-4
DOIs
Publication statusPublished - 2018
Event12th International Seminar Numerical Analysis of Weldability - Graz, Austria
Duration: 23 Sep 201826 Sep 2018

Seminar

Seminar12th International Seminar Numerical Analysis of Weldability
CountryAustria
CityGraz
Period23/09/1826/09/18

Keywords

  • Solidification Cracking
  • Hot Cracking
  • Steel
  • Laser Welding
  • Automotive
  • Advanced high strength steels (AHSS)

Fingerprint Dive into the research topics of 'Residual stress measurements and model validation of single and double pulse resistance spot welded advanced high strength steel'. Together they form a unique fingerprint.

  • Cite this

    Eftekharimilani, P., Gao, H., Huizenga, R., van der Aa, EM., Amirthalingam, M., Richardson, I., & Hermans, M. (2018). Residual stress measurements and model validation of single and double pulse resistance spot welded advanced high strength steel. In C. Sommitsch, N. Enzinger, & P. Mayr (Eds.), Mathematical Modelling of Weld Phenomena 12 (Vol. 12, pp. 401-415). Verlag der Technischen Universitat Graz. https://doi.org/10.3217/978-3-85125-615-4-22