Energy absorption mechanism of Al–steel bilayer sheets produced by cold roll welding during wedge tearing

The behavior of Al–steel bilayer sheets produced by cold roll welding is investigated through the wedge tearing process. It is observed that through tearing the energy absorbed by cold roll welded bilayer sheets is larger than that of non-welded ones, even though all parameters are identical. Also bilayer sheets with low bond strength have the same energy absorbed by non-welded bilayer sheets. By investigating all contributing mechanisms in tearing and mechanical properties of composite layers and developing theoretical equations, it is concluded that bending of sheets through wedge tearing plays a major role in difference of energy absorbed by welded and non-welded bilayer sheets. Moreover, there is a good correlation between experimental data and theoretical equations developed for predicting the load–displacement curves of tearing and energy absorption of Al–steel bilayer sheets.