| Currently there is great interest in using tailor welded blanks for automotive applications. The welding technology for steel has advanced sufficiently that the weld metal is stronger than the base material. However, there is a need to understand the forming characteristics of tailor welded blanks. In this study, three formability issues of tailor-welded blanks were addressed: the formability of different weld types, the comparison of different testing methods and the prediction of the forming behavior using the finite element method. It was found that there was almost no difference in formability between the mash seam and laser welding processes. The OSU Formability Test ranked the welded blanks in the same way as the tensile test, while the dome testing did not. However, the dome test was useful for analyzing the movement of the weld line. A finite element model using the commercial code ABAQUS was able to predict the weld movement in the dome test and to determine what variables had the greatest effect on weld movement. The properties of the base materials and the boundary forces dominate weld movement, while the local properties of the weld bead were insignificant. The in-house code SHEET-3 successfully modeled a scale fender geometry and predicted the weld movement of a tailor welded blank and found the weld movement to be very sensitive to the boundary forces around the sheet. |
