(上海交通大学 机械与动力工程学院，上海 200240)
摘 要: 针对AZ31镁合金板材深冲过程中的制耳现象，提出一种基于晶体塑性理论的镁合金板材冲压制耳行为的预测方法。首先，从镁合金温成形时的塑性变形机理(即滑移和孪生共同作用)出发，建立耦合滑移和孪生的适合密排六方结构(HCP)金属的晶体塑性本构模型；在此基础上，编制相关程序，通过结合理论、模拟和实验的方法确定镁板微观变形机制组合和多晶体模型参数两个关键因素，构建了适用于镁合金板材大变形的晶体塑性有限元仿真模型；最后，采用HCP板材大变形晶体塑性有限元模型对AZ31镁合金板材的杯形件冲压过程进行有限元仿真，并利用实验结果从制耳轮廓和变形织构两方面验证HCP晶体塑性理论预测冲压制耳的准确性。实验与模拟结果均表明，冲压杯形件呈现出显著的偏离轧向45°制耳轮廓以及(0001) 织构组分和拉伸孪晶组分。
关键字: 镁合金；冲压制耳；晶体塑性有限元；织构
（School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:In order to predict the earing behavior during deep drawing of magnesium alloy accurately, a crystal plasticity theory combined with finite element method was proposed. First of all, based on the microscopic nature of plastic deformation during warm forming, a crystal plasticity constitutive model coupling slip and twinning was established for magnesium alloy with hexagonal close packed (HCP) structure. Then, in order to establish crystal plasticity finite element model for large deformation, the secondary development interface (VUMAT) of the commercial finite element software ABAQUS/Explicit and Fortran programming language were used, the deformation modes and model parameters were determined by combining the theory, simulation and experiments. Finally, the commercial rolled AZ31 magnesium alloy sheets were simulated during deep cup drawing using the HCP crystal plasticity finite element model, and the predicting method is validated by comparing with experimental results from both earing profile and deformation texture. Both the experimental and simulated results show significant earings at 45° away from rolling direction and texture components of (0001) and tensile twinning.
Key words: magnesium alloy; earing; crystal plasticity finite element; texture
