The analyse on the process of multi-point forming for dish head

Multi-point forming (MPF) can form a variety of part shapes without the need for solid dies. Multi-step forming and sectional forming are the common use forming method in MPF. Multi-step forming runs up to the final shape by deformation of each step while sectional forming achieves the final shape by deformation of each region of sheet metal. In this paper the forming rules and characteristics of this two forming methods on the process for dish head are studied. Both numerical simulation of once forming and multi-step forming process for sphere surface are done. Wrinkles, deformation and strain are compared. The result shows that multi-step forming makes deformation more equably. It can restrain wrinkle effectively and improve the deformation capacity by optimizing the deformation path. The sectional MPF numerical simulation on the process for dish head are also carried out. Itʹs deformation characteristics, forming region and transition region are studied. Finally MPF process design is made and the forming tests are done. The result shows that dish head can be primely shaped with multi-point press under the appropriate MPF forming process.