5A06管材力学性能测试及其缩口成形性的有限元分析

Mechanical Property Testing and Finite Element Analysis of Nosing Formability of 5A06 Tube

目的研究直径Φ20 mm、壁厚2 mm的5A06铝合金管在单向拉伸试验下的表现以及其在外支承球形缩口成形中的变形特点。方法利用管材准静态单向拉伸试验测试其力学性能,获得真实应力-应变曲线,再结合有限元软件ABAQUS分析管缩口成形的应力应变特征。结果 5A06管在拉伸中表现出良好的应变硬化能力,并呈明显的锯齿波动屈服特性。模拟结果显示缩口中的管坯整体处于周向、轴向压应力状态;主变形区内,轴向应变从缩口口边的拉应变逐渐变为主变形区向直壁过渡区域的压应变;除主变形区外,直壁部分的壁厚也有所增加。Φ20 mm×2 mm的5A06管在模拟中的极限缩口系数约为0.410。结论Φ20 mm×2 mm的5A06管在外支承球形缩口中的模拟成形极限较高,有限元分析作为缩口成形模具和工艺设计的前一步工作,其结果有一定的参考价值。

The paper aims to research performances of 5A06 aluminum tube （Φ20 mm, wall thickness： 2 mm） during the unidirectional tensile test and its deformation characteristics in nosing forming of external spherical bearing. Its mechanical properties were tested in quasi-static unidirectional tensile test of tubes to obtain the true stress-strain curve. The stress-strain characteristics of nosing forming were analyzed in combination with finite element software ABAQUS. The results showed that 5A06 aluminum tube had strain hardening capacity in stretching and presented a fluctuant yield feature. Simulation results indicated that tube blank in nosing suffered from surrounding and axial pressure and stress overall; in the primary deformation zone, the axial strain changed from stretching strain at nosing edge to compression strain from the primary deformation zone to the vertical wall transition zone; in addition to the primary deformation zone, thickness of the straight-wall also increased to some extent. The ultimate nosing coefficient of Φ20 mm×2 mm 5A06 tube was nearly 0.410. The simulation forming limit of Φ20 mm×2 mm 5A06 tube in nosing external spherical bearing of is high. Since finite element analysis is a preceding step of nosing forming and process design, its results are believed to have certain reference value.