Showing papers on "Hydroforming published in 1987"
TL;DR: In this paper, a new kinematically admissible velocity field is suggested for the upper bound solution of three-dimensional hydroforming of regular polygonal boxes, in order to maintain the uniform wall thickness a back-up fluid pressure is controlled to vary with respect to the punch position during the hydroforming process.
16 citations
TL;DR: In this paper, a simple model was developed to describe the effect of blank holding load on the deformation of aluminum, brass and copper specimens, and the size of the die shoulder radius was also considered; and the workhardening characteristic of sheet metal was linearized by the use of a suitable strain measure derived from the experimental curve.
Abstract: During hydroforming of sheet materials into axisymmetrical shells, varying the blank holding load causes a change in the draw-in condition of the flange, and hence deformation. By assuming the shell surface to be spherical and the infeeding material to be unstretched and uniformly distributed along the shell surface, a simple model is developed to describe the effect of blank holding load on the deformation of aluminum, brass and copper specimens. In this model, the size of the die shoulder radius is also considered; and the workhardening characteristic of sheet metal is linearized by the use of a suitable strain measure derived from the experimental curve. It is observed that the theoretical results compare well with experimental results.
5 citations