非関連流れ則に基づく異方性塑性構成式 (第2報)

抄録

In metal forming, importance of precise fracture prediction has been increased. However, as the use of anisotropic cold rolled metals such as aluminum alloy sheets increased, fracture prediction has become difficult. In this study, fracture initiation is represented as the result of local bifurcation, which is analyzed mechanically reasonably by using a local bifurcation theory. To represent local bifurcation appropriately, we have adopted the 3D bifurcation theory based on the anisotropic plastic constitutive equation in which the rotation of stress rate tensor is introduced to express plastic instability. To evaluate this constitutive equation, the non-associated flow rule material model that has been proposed by the author is applied. In this report, fundamental formulas and analytical examples on formability evaluation are presented.