6061铝合金薄壁管绕弯成形数值模拟及实验研究

Numerical simulation and experimental research on the rotary bending of 6061 aluminium alloy tube

通过单向拉伸试验获得6061-T6铝合金管（Φ50.8 mm×1 mm）的基本力学性能数据,拟合建立了材料的本构方程;对异型弯管的数控绕弯过程进行有限元模拟,研究了芯棒与管材间间隙值、芯棒伸出量、芯头个数对弯管成形质量的影响规律,分析发现,最优间隙值为1.05 mm,并获得了90°-100°弯管时两个弯曲段的回弹角和弯曲角关系曲线。模拟结果表明,第1次弯曲角为96°、第2次弯曲角为94.5°时可得到平行度较好的异型弯管。最后通过绕弯实验,将实验结果与仿真模拟进行对比,验证了模拟所得规律和材料模型的准确性。

The constitutive equation of material was built based on the basic mechanical properties of 6061 -T6 aluminum alloy tube （ Φ50. 8 mm ～ 1mm） obtained by tensile test. The CNC rotary bending process of shaped bending tube was simulated numerically. The influences of the clearance between the mandrel and tube, mandrel extension and the number of core head on forming quality were stud- ied. The result show that the most appropriate clearance value is 1.05 mm. The relationship curves between springback angles and ben- ding angles of the two bending tube 90° - 100°were gained. The simulated result shows that a better parallel precision of the shaped tube can be obtained when the first bending angle is 96°and the second bending angle is 94. 5°. The accuracy of simulation and constitutive e- quations were verified by comparing the results of tests with simulations.