| Spinning easily manufactures the product of seamless hollow rotary body. It has many advantages, including good deformation conditions, excellent product performance, precise dimensional tolerance, high material utilization ratio, great product categories and so on. It has been widely applied in weapons, aviation, astronavigation, civil and other metal precision forming technology departments. In the process of manufacture, many process parameters affect the qualities of spinned parts, engineers have to establish process parameters by trial-and-error approach. Finite element numerical simulation technology may reduce cost, increase production efficiency and provide a guide for the process design and experimental study.In this dissertation, outside spinning of tube and interior spinning of tube with inner rib are analyzed. Firstly,3D FEM models of these forming processes are established under MSC.Marc software environment, and then the deformation mechanism and the influencing laws of technological parameters are investigated.First, by means of finite element theory, the hexahedron element has been used for plotting the blank. Clamp, mandrel and roller have been discreted respectively. Some key technologies have been solved, including friction condition, boundary condition and roller path etc. Then, reasonable FEM models of spinning of tube are established.Based on the model established above, the distribution and variation features of the stress and strain during outside spinning of tube deformation have been obtained. The effects of spinning modes and technological parameters on spinning forces and workpiece quality have been analyzed. The results demonstrate that spinning forces increase with the increasing of reduction, feed rate and fillet radius, especially the radial spinning force. With the increasing of the forming angle, the total spinning force and radial spinning force decrease rapidly, but the axial spinning force increases slightly.Deformation law and variation tendency of spinning force have been researched during interior spinning of tube with rib by simulation. The influence of reduction and feed rate on metal flow, dimensional precision and height of the inner rib are studied. Researches show that with the increasing of reduction, dimensional precision decreases and the height of the inner rib enhances a little. With the increasing of feed rate, dimensional precision significantly improves, but the height of the inner rib reduces rapidly when feed rate is under 1.5 mm/r. |
