Thickness change and springback of cold roll bonded aluminum/copper clad sheets in air bending process

Abstract

In this article, an advanced analytical formulation is developed to predict thickness change of an aluminum/copper clad sheet. Springback analytical formulation is also introduced using the combination of advanced and primary bending theories in air bending process. Experiments were performed to verify analytical results and to investigate the effect of different geometrical parameters such as punch stroke, die opening, punch radius and setting condition on the springback. It was observed that die opening had the most striking effect, while setting condition had a negligible effect on springback. On the other hand, setting condition played a crucial role on thickness change in bent clad sheets. Clad sheet thickened in the Al/Cu setting condition, while in the Cu/Al setting it thinned. Finite element method simulation was also applied to verify analytical predictions of the thickness change and study stress distribution in the layers of the clad sheet. Good correlation was observed between analytical and numerical results.