Abstract:

In order to further investigate the neck-spinning mechanism and conduct practical manufacturing,the mandreless neck-spinning with a single roller is simulated based on the 3 D elastic-plastic FEM (Finite Element Method)model by means of the FEM software MARC.The deformation mechanism and the distributions of stress and strain in the process of the mandreless neck-spinning are also analyzed.The results show that(1)the deformed metal in the contact zone between the roller and the blank is in a 3 D compressive stress state;(2)the axial tensile strain is gradually transformed into the compressive strain from the deform ed zone to the undeformed zone. while the radial compressive strain is transformed into the tensile one;(3)with the increment of the reduction of blank radi-US,the equivalent stress increases,and the maximum radial stress appears at the opening and the inner wall of the transitional circular zone;and(4)the thinnest area,namely,the dangerous position at which crack may occur.appears at the transitional circular zone.The simulated results accord well with the actual spinning process,which lays a theoretical foundation for the establishment of neck-spinning technology.

Key words: numerical simulation, conventional spinning, mandreless spinning, neck-spinning, finite element method