Determination of Constitutive Parameters of Plastic Materials Using a Finite-Element Polycrystalline Model

Abstract

We previously proposed a constitutive expression of plastic deformation which can incorporate the directional dependence of the plastic strain increment ε^P on the stress increment σ. The expression was given in terms of two transition parameters μ(α) and β(α) which denote the magnitude and the direction angle of the plastic increment, where α denotes the direction angle of the stress increment measured from a particular direction, termed "natural direction", in which the direction of the stress increment coincides with that of the plastic strain increment. The expression can be utilized once we obtain the parameters μ(α) and β(α) through experimentation on industrial materials and/or theoretical studies such as polycrystalline model analyses. In this report, a computer code for a finite-element polycrystalline model is developed and used for the investigation of the variations of the two constitutive parameters μ(α) and β(α).