Influence of the orthotropic behaviour on defects prediction in cup drawing, reverse redrawing and expansion

Abstract

Finite elements analysis is commonly used in the cans tool design since it allows predicting different sheet metal defects and instabilities that significantly affect the efficient production of beverage cans. These defects include earing, due to the material orthotropic behaviour, thinning and fracture. The numerical prediction of these kind of defects is more complex when different combinations of strain paths are involved. The process conditions considered in this work involve the drawing of a cylindrical cup, the reverse redrawing and the expansion. The two materials under analysis are an AA5352 aluminium alloy and a TH330 steel. The materials orthotropic plastic behaviour is modelled with a non-quadratic yield criterion. The results show that changes in the yield surface lead to slight changes in the earing profile and in the location were strain localization occurs. Moreover, the numerical model must describe in detail the process conditions, since they may affect the formability prediction.