Observations of cyclic deformation behaviors of aluminum sheet and constitutive modeling

Aluminum sheet metals have been widely utilized for a light weight construction of automobile. However, these metals still remain one of the difficult materials to predict the accurate final shapes after press forming processes, because of several mechanical features such as plastic anisotropy of yield stress and small Lankford value. In order to solve the problems, the present author has developed a new constitutive model. The model can describe accurate non-proportional hardening behaviors of aluminum sheet metals. In the present research, some experimental procedures were carried out to reveal the mechanical properties of an aluminum sheet under proportional and non-proportional deformations. The comparisons between experimental data and the corresponding calculated results by the proposed constitutive model confirm the advantages of our model.