大型筒体对轮强力旋压成形特征与规律研究

目的 研究大直径薄壁筒体在对轮强力旋压过程中的应力–应变分布情况和材料流动特征，探明减薄率、进给比和主轴转速等工艺参数对成形结果的影响规律。方法 利用Forge仿真平台建立2.25 m级5052铝合金筒体对轮强力旋压的有限元模型，分析筒体成形过程中的应力–应变状态和主要工艺参数对成形精度与旋压成形力的影响规律。结果 在对轮旋压成形过程中，筒体内外侧应力–应变呈对称分布，成形区域内材料呈扇形流动。工艺参数对成形工件壁厚精度和旋压成形力的影响主次顺序为:减薄率＞进给比>主轴转速。结论 各工艺参数的增大均会降低工件的壁厚精度，减薄率和进给比的增大会引起旋压成形力增大，而主轴转速增大会使旋压成形力轻微减小。

Characteristics and Rules of Counter-roller Flow-forming of Large Tube

The work aims to study stress-strain distribution and material flow characteristics of large-diameter thin-walled tube during counter-roller flow-forming, and explore the effects of process parameters such as thinning ratio, feed ratio and spindle speed on the forming results.A finite element model of 5052 aluminum alloy tube with a diameter of 2.25 m was established with Forge simulation platform. The stress-strain state in the tube forming process and the effects of main process parameters on the forming results were analyzed. The results showed that in the process of counter-roller flow-forming, the stress and strain on the inner and outer sides of the tube were symmetrically distributed, and the material flowed in a sector in the forming area. The primary and secondary order of the effects of process parameters on the wall thickness accuracy and forming force of formed workpiece was:thinning ratio>feed ratio>spindle speed. The increase of process parameters will reduce the wall thickness accuracy of the workpiece. The increase of thinning ratio and feed ratio will increase the forming force of flow-forming, while the increase of spindle speed will slightly reduce the forming force of flow-forming.