| Abstrakt: |
The purpose of this investigation was to obtain a rigorous analysis of the drawing of a plastic sheet between two fixed cylindrical surfaces. A number of solutions have recently been given (1, 2, 3, 4, 5) in which the following fundamental assumptions are used: (a) The material between the cylinders is in a state of plane plastic flow and behaves according to the Saint Venant-Mises theory; (b) the normal stress in the direction of drawing σx and the normal stress at the boundary σn are the principal stresses, (c) the horizontal stress σx is constant over each cross section. In the present treatment only assumption (a) is retained. Shevchenko (4) has recently solved this problem assuming that the shearing stress at the walls is proportional to the relative velocity between the wall and the plastic material. |
