In this study, an elastic-plastic model with yielding described by a newly proposed orthotropic yield criterion was used to model the unusual deformation of a strongly textured AA6060 alloy. Available experimental data from tension tests and results of crystal plasticity simulations were used to determine the anisotropy coefficients involved in the yield criterion. Virtual material tests using a recent polycrystalline model were performed to obtain flow stresses for loadings where experimental data were not available. The capability of the elastic-plastic model to account for the distinct anisotropy of the material is demonstrated through comparison of finite element simulations and experimental tests on both smooth and notched axisymmetric specimens of the AA6060 alloy. Specifically, for the smooth specimen, the model predicts that the minimum cross-section evolves from a circle to an ellipse while for the notched specimens, the minimum cross-section evolves from a circular shape to an approximately rectangular, or rhomboidal shape, respectively as observed in the experiments. This model can be easily implemented in finite element codes, requires reduced CPU time compared to crystal plasticity finite element simulations, and can be applied in simulations of large-scale structural applications.

在这项研究中，使用新提出的正交各向异性屈服准则描述的具有屈服的弹塑性模型来对强织构AA6060合金的异常变形进行建模。来自拉伸试验的可用实验数据和晶体可塑性模拟的结果用于确定屈服准则中涉及的各向异性系数。在没有实验数据的情况下，使用最新的多晶模型进行了虚拟材料测试，以获取载荷的流动应力。通过比较有限元模拟和对AA6060合金的光滑和缺口轴对称试样进行的实验测试，证明了弹塑性模型解决材料独特各向异性的能力。具体来说，对于光滑的样品，该模型预测，如在实验中观察到的那样，最小横截面从圆形演变为椭圆形，而对于带缺口的样品，最小横截面从圆形演化为近似矩形或菱形。与晶体可塑性有限元仿真相比，该模型可以轻松地用有限元代码实现，并且需要减少CPU时间，并且可以应用于大型结构应用程序的仿真中。