铝合金变直径管材旋弯渐进成形规律有限元模拟研究

A double-roller flexible bending die for the spinning-bending incremental forming was designed, which can apply circumferential restraint to the tube and enable adaptive rotation during the forming process. Compared with the traditional circular type single-roller bending die, the new type of double-roller flexible bending die can effectively reduce the bending force, improve the forming stability and suppress the cross-section deformation of the tube. On these bases, the whole-process finite element model for the spinning-bending incremental forming of aluminum alloy tube was established. By comparing with flexible bending forming, the coupling effect laws of spinning-bending deformation on the forming results were analyzed. It is found that the introduction of bending step on the basis of spinning causes a certain degree of cross-section deformation and uneven wall thickness. The introduction of spinning step on the basis of bending reduces the cross-section deformation of the bending section, increase the difference between the intrados and extrados wall thickness, increase wrinkling tendency, and reduce the springback after forming.