Experimental and theoretical analysis on formability of aluminum tailor-welded blanks

This paper presents an investigation on forming limits of tailor-welded blanks (TWBs) made of 5754-O aluminum sheets using both experimental and numerical approaches. TWBs may be composed of two or more welded flat metal sheets of different thicknesses, shapes, or mechanical properties. Due to the existence of weldment and the individual configurations of base blanks, TWBs should be considered as heterogeneous in its structure. The mechanical properties of those base metals and weld metal required for the simulation were measured individually. With the aid of the acquired data, finite element simulations for analyzing the forming process of TWBs were carried out using a general purpose finite element package, LS-DYNA. A localized necking criterion based on the vertex theory was employed to predict forming limit strains and failure locations of the aluminum TWBs. The theoretical predictions were satisfactorily validated with those obtained from the experiments.