Analytical Approach to Predict Anisotropic Material Properties from Cup Drawings

Abstract

Typical beverage can alloys have limited elongation (about 3-5%) under uniaxial tension. However, in order to obtain correct material properties, it is recommended to have elongations over 10 percent. Thus, it is very difficult to predict stable r-value and stress directionalities experimentally, which are essential for FE simulation of rigid-packing sheet forming operation. An innovative simplified analytical approach that relates the earing profile to r-values and yield stress directionalities is presented in this work. R-value and yield stress data were predicted from earing profiles of two separate cup drawing processes. By doing so, concerns for the limited elongation along a uniaxial direction can be eliminated. The new methodology can conveniently be used as a supplementary tool when the uniaxial testing is limited. The model was verified with a can stock material.