一軸応力状態における非硬化領域の概念を有する修正サブレイヤーモデルの提案

Abstract

In this study, the constitutive model which is capable of describing the behavior of metals under the uni-axial cyclic loading is suggested. Many constitutive models for multi-axial stress problems have been proposed. In particular, we have focused on the sub-layer model because it can be satisfied with Masing's rule and be understood easily from the perspective of the mechanics. It is inevitable to incorporate appropriate hardening rules into the constitutive model in order to represent hardening phenomena. In the present work, at first, new hardening rules for the sub-layer model are proposed to overcome shortcomings for the classical sub-layer model where hardening rules are defined for each layer respectively. Then, the concept of the non-hardening region is applied to the sub-layer model with the new hardening rule since the only new hardening rules are not enough to describe the complex hardening phenomena. Finally, the validation of the present model is conducted through comparisons between numerical results and experimental results under the uni-axial stress field.