Abstract: The different strength combination and different thickness of materials play important role in the formability of tailor-welded blank (TWB). With bead and without bead separately, the formability of tailor-welded blanks square cup is analyzed by numeric simulation technology in different conditions：different thickness and different strength combination of TWB’s materials. Also, the affect of the draw bead on the displacement of weld-line is investigated. Further, the laws influencing the formability of TWB square cup are summarized, and an approach is presented to reduce the displacement of weld-line. The results indicate that controlling the thickness ratio of two blanks up to more than 0.5, choosing lower strength material for thicker blank in condition without bead and for thinner blank in condition with bead, and reducing the difference of thickness between two blanks can improve the forming capability of TWB and vice versa. Draw bead can reduce the influence of strength difference on forming performance and also reduce the displacement of weld-line. Practice shows that designed a draw bead at the direction perpendicular to weld-line can improve the stiffness of front floor board part and reduce the displacement of weld-line.

Key words: Different thickness, Draw bead, Strength combination, Tailor-welded blank, Weld-line movement