Demarcation Line of Metal Flow with Plastic Change of Workpiece Form

Problems to define the shape of the metal flow demarcation line are considered for processes of solid stamping of parts with thin sheets. Analytical relations are derived for the case of the part contour plan being multiply connected and consisting of arcs. The metal flow demarcation line is a geometric locus of points, being at equal distance from the contour arcs, and presents the hyperbola.