An Investigation of Springback Stresses in Deep-Drawn Cups Using Diffraction Techniques 2005-01-0498
Prediction of springback has become a major focus in sheet metal forming. Validation of finite element codes that are being developed to predict springback require accurate property data and a more complete understanding of the residual stresses that are involved. To provide experimental data for these calculations, neutron and synchrotron X-ray diffraction measurements were carried out to determine the through-thickness distribution of axial and hoop (or tangential) residual stresses in deep-drawn steel and aluminum cups. The techniques are able to provide true spatial resolutions as low as 0.05 mm for a strain measurement on cups with ≤ 1 mm wall thickness. It was found that the stresses exhibit non-linear gradients through the thickness that also depend on the axial position.
T. Gnaeupel-Herold, T. J. Foecke, H. J. Prask, R. J. Fields, L. E. Levine, Z. Cedric Xia, Ulrich Lienert
National Institute of Standards and Technology, FORD Scientific Research Laboratory, APS, Argonne National Laboratory
SAE 2005 World Congress & Exhibition
Innovations in Modeling and Testing of Steel Structures for Automotive Applications, and Front and Rear Bumper Systems-SP-1954, SAE 2005 Transactions Journal of Materials and Manufacturing-V114-5