The study is concerned with the analysis of axisymmetric hydroforming with controlled pressure by the rigid-plastic finite element method. The finite element method is employed to obtain the detailed information including the distribution of stresses and strains and geometry changes.
Experiments are carried out for hydroforming of cold-rolled steel sheets with the developed CNC hydroforming press which is pressure-controlled according to the fluid pressure vs stroke relationship given by the upper-bound. Three types of punches are used for the experiments.
The computed results are in good aggrements with the experimental observation in geometric change and thickness variation. The present analysis permits the prediction of stresses, strains, geometric changes and to some extent the position in which necking will occur. The effects of Lankford value on thickness strains in hydroforming are also discussed. It is thus shown that the present method can be applied to the effective design of axisymmetric hydroforming processes.
