Analytical Approach to Predict Anisotropic Material Properties from Cup Drawings

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. Rvalue 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.