Strong initial and induced anisotropies, observed in the deformation of Mg alloys, have restricted their industrial applications. The initial anisotropic behavior is caused by the initial texture of Mg sheets which are fabricated by successive rolling operations. This behavior could be well described by appropriate yield criteria. However, the texture evolution inside the material induces the distortion of the yield surface, which has strong effects on the hardening and damage evolution. Classical isotropic and kinematic hardening could not precisely describe the induced anisotropic hardening. Therefore, distortional hardening, describing the shape alteration of the yield surface, should be considered in modeling the mechanical behaviors of Mg alloy sheets. In this study, a plasticity model fully coupled with isotropic damage for Mg alloys is proposed, and the constitutive equations are formulated within the thermodynamic framework using state variables. The current constitutive model could accurately reproduce the stress–strain evolution under tension, shear and compression for Mg alloy AZ31. In addition, both of the initial anisotropic yield surface and the subsequent distorted yield surface are captured correctly, and the failure under combined loading path is well predicted by the proposed model.

在镁合金的变形中观察到的强烈的初始各向异性和诱导各向异性，限制了它们的工业应用。初始各向异性行为是由通过连续轧制操作制造的Mg板的初始织构引起的。适当的屈服标准可以很好地描述这种行为。但是，材料内部的纹理演变会引起屈服面变形，从而对硬化和破坏演变产生强烈影响。经典的各向同性和运动学硬化不能精确地描述诱发的各向异性硬化。因此，在对Mg合金板的力学行为进行建模时，应考虑描述淬火表面形状变化的变形硬化。在这个研究中，提出了一种与镁合金各向同性损伤完全耦合的塑性模型，并利用状态变量在热力学框架内建立了本构方程。当前的本构模型可以准确地再现镁合金AZ31在拉伸，剪切和压缩状态下的应力-应变演变。此外，初始各向异性屈服面和随后的扭曲屈服面都可以正确地捕获，并且所提出的模型可以很好地预测组合荷载路径下的破坏。