Bending Of Profiled Circular Workpieces

Bending of profiled circular workpieces is a new process for manufacturing the large size circular parts, such as flanges. Its main idea is that first of a whole circular parts is designed as several segments, then these segments are bent into arcs and the arcs are welded together into a circular part in fabricating site. An advantage of the process is that machining with large-sized vertical lathe is not used. Therefore, precision of the bending and the deformation of circular workpieces are very important for the process.In this paper, the process and classification of bending profiled circular workpieces were introduced. Bending processes of symmetry and asymmetry section parts were investigated by numerical simulation and experiments,The ABAQUS software was used for simulating the bending process of circular parts. Two different kinds profiled billets and the billet with rectangular were bended. The distribution and variation of curvature and stress of them during the forming process were analyzed, and the influence of feed length and press times, and over press amount were also analyzed. The stress and curvature distribution of a pair of asymmetry section parts were studied, the simulation results show that no defects of twist and lateral bending occur if it was bent with a pairs.Three different kinds profiled billets and the billet with rectangular were bended in the experimental research, the experiments were proceeded by adjusting feed length, press times, over press amount, the experimental results are well in agreement with the simulation results. Then the mechanism of the defects of twist and lateral bending of asymmetry section parts were analyzed, it revealed that the reasons of defect of twist and lateral bending were the asymmetric distribution of the stress in the parts. The dimension variation of cross section was analyzed theoretically, and it was also verified by experiment. The influence of constraint on the twist and laterals bending was also studied experimentally, and it is shown that constraint benefit to depress the defects.