INFLUENCE OF WELD ORIENTATION ON FORMING LIMIT DIAGRAM OF SIMILAR DISSIMILAR THICKNESS LASER WELDED-JOINTS/

The drive towards reduced car body weights and improved safety could b e met by the introduction of tailored welded blanks at the design stag e. A tailored welded blank is a single panel formed by welding two or more different materials together to form a single composite sheet, wh ich is then subsequently pressed. The materials within a single panel can have different properties, such as high strength or high corrosion resistance, and may even be of different thicknesses. The problems as sociated with the production of such panels come mainly at the stampin g stage, in the form of weld or parent material failure. Work has begu n with small scale cupping tests of laser welded samples to establish the forming behaviour of the weld. Forming limit diagrams have been co nstructed for several welded and unwelded material combinations to est ablish the limiting strain conditions during a forming operation