航空铝合金薄壁件铣削变形预测研究

Prediction of Deflection for Machining Thin-Wall Aerospace Aluminum Alloy Component

铝合金比强度较高,广泛应用于航空航天、精密仪器和武器等行业,这些行业的零件多是薄壁件,其刚度较差,加工过程中易产生变形而使加工精度降低。为提高薄壁零件加工精度,需对其加工过程中的变形量精确预测。基于此,以J-C本构方程为基础,考虑材料热力学动态性能和断裂准则对铣削变形的影响,建立薄壁零件铣削变形量预测模型。利用UG软件建立铝合金7050-T7451薄壁特征工件。利用Deform-3D对材料本构模型、切屑分离和切屑断裂等进行描述,形成铣削加工有限元模型,对铣削变形量进行预测。进行薄壁件铣削试验,对比仿真预测结果与实验测量结果,证明了预测模型的可行性。

Due to the high specific： strength, thin - walled parts have been widely used in aerospace, precision instru- ments and weapons industries. However, the rigidity of thin - walled parts is very low, deflection is prone to be induced during machining which will reduce the part finished accuracy. In order to improve the machining precision of thin - walled parts, the amount of deformation must he accurately predicted. Therefore, an accurate and practical prediction model of simulation of milling deformation is developed based on the J - C constitutive equation, UG modeling and DEFORM - 3D simulation. The effects of the material properties and fracture criterion on the machining deformation are considered during simulation modeling. Firstly, the thin - walled part is created by UG. Then, a finite element model of milling is estab- lished by modeling the material constitutive relationship, chip fracture and separation criterion. A simulation procedure is proposed to simulate the thin - walled maehining feature of A17075 alloy by the DEFORM - 3D software. Lastly, the ma- chining experiments of thin - walled parts are conducted to validate the feasibility of the proposed simulation model.