Takayuki Nonaka

Simplified Three-Dimensional Finite Element Simulation of Shear Spinning Process Based on Axisymmetric Modeling☆

Abstract A simplified three-dimensional method for simulating plastic deformation in a shear spinning process of disks in a comparatively short computing time is proposed on the basis of the rigid-plastic finite element method using axisymmetric modeling. In this method, the shear spinning process is approximated as a forming process with a ringed die having the same cross-sectional shapes as the roller. The effects of the virtual shear deformation in the hoop direction and the incremental deformation in the shear spinning process are introduced into the axisymmetric modeling. A shear spinning process of disks having a taper flange is simulated by the proposed method. The forming limit is predicted from the pileup just before touching the roller in the finite element simulation. In addition, an actual shear spinning process of a large wheel disk for a bus and truck is simulated.

Increase of Wall Thickness around Corner of Multi-Stage Drawn Cup with Flange Using Conical Punches

The wall thickness around an inner corner in 3-stages formed cups with a flange was increased by means of conical punches in the 1st and 2nd stages. Since the strength of the formed cups is greatly improved by the increase in wall thickness, the weight of the formed products is reduced by an optimum distribution obtained from the increase in wall thickness. The increase in thickness around the inner corner is obtained by compressing the side wall and conical bottom of the cup in the 3rd stage. As the punch angle increases, the increase in thickness at the inner corner becomes large. The amount of compression is expressed by a drawn volume after the 2nd stage. A maximum 9% increase in wall thickness around the inner corner was successfully obtained for the punch angle of 25º.