The Effect of Geometric Discontinuity and Weld Region on Formability of Tailor Welded Blanks (TWB)

Numerous advantages of application of tailor welded blanks (TWBs) in automobile industry, namely reduction of weight, fuel consumption and air pollution, have made the manufacturers eager to investigate in this field. In this research, the effect of weld zone presence on the formability of transversely CO2 laser welded TWBs was studied experimentally and numerically (FE-method). The studied TWBs were consisted of IF-steels with different thicknesses (0.8 and 1.2 mm), and limiting dome height as well as forming limit diagram were used for formability assessment. Experiments in regard with limiting dome height test showed that the decisive factor in decreasing the dome height is geometric discontinuity and the effect of weld zone is about 6%. Moreover, simulation results indicated that the consideration of weld zone did not have any observable effect on limiting strains, although tearing occurred at lower punch stroke.

Keywords:

tailor welded blanks , geometric discontinuity , weld region