Material Model based on Non-associated Flow Rule with Higher-order Yield Function for Anisotropic Metals☆
Material Model based on Non-associated Flow Rule with Higher-order Yield Function for Anisotropic Metals☆
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DOI：
10.1016/j.proeng.2014.10.099
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
T. Oya;J. Yanagimoto;Koichi Ito;G. Uemura;N. Mori
中科院分区：
文献类型：
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作者：
T. Oya;J. Yanagimoto;Koichi Ito;G. Uemura;N. Mori
提出了具有初始各向异性的材料塑性本构模型的新表达式。应允许塑性应变率张量在一定程度上跟随应力率张量的旋转，在塑性不稳定的情况下，应力率张量立即从当前应力张量的方向旋转。为此，所提出的模型采用了非关联正态模型，其中塑性势函数的定义与屈服函数无关。还提出了等效塑性应变率的显式表达式，该表达式与对应于所提出的屈服函数的定义的等效应力进行塑性功共轭。这对于表达具有塑性流动应力各向异性的材料的广义加工硬化规则非常重要。所提出的理论有望克服相关塑性流动理论中的严重问题。
A new expression for the plastic constitutive model for materials with initial anisotropy is proposed. A plastic strain rate tensor should be permitted to follow, to a certain extent, the rotation of the stress rate tensor, which rotates instantly from the direction of the current stress tensor as in the case of plastic instability. For this purpose, a non-associated normality model, in which the plastic potential function is defined independently of the yield function, has been adopted in the proposed model. An explicit expression for the equivalent plastic strain rate, which is plastic-work-conjugated with the defined equivalent stress corresponding to the proposed yield function, is also presented. This is important for expressing a generalized work-hardening rule for materials with plastic flow stress anisotropy. The proposed theory is expected to overcome the serious problems in the associated plastic flow theory.