Sheet metal forming processes induce residual stress in the final product due to the plastic deformation. The residual stress leads elastic recovery of the formed part called springback which causes shape errors in final product. This error becomes se...
Sheet metal forming processes induce residual stress in the final product due to the plastic deformation. The residual stress leads elastic recovery of the formed part called springback which causes shape errors in final product. This error becomes serious especially for high strength steels which are widely used in auto-body structures, then the evaluation of the amount of springback becomes important for high strength steels. This paper investigates the spring back behavior of DP780 steel sheets after the U-bending process using the geometry of the standard U-shape from NUMISHEET’93. The amounts of springback were measured with the variation of the blank holding force, forming speed and material anisotropy.