Determination of the limiting drawing coefficient in the deep drawing of conical cups

The limit deformation of conical cup drawing can be expressed by the limiti ng drawing coefficient [m] (=[D-d/D-0]). where m is the drawing coefficient of conical cups, D-d the die diameter, and D-0 the initial blank diameter, [m] the reciprocal of the Limiting drawing ratio. Based on the internal re lation between conical cups and cylindrical cups, the practical calculation equation of [m] is derived by mechanical analysis, and the forming limit c urves expressed by [m] and the limiting drawing coefficient in the first dr awing are given. The limiting drawing coefficient given in this paper is pr oven experimentally to be accurate and convenient. (C) 2001 Elsevier Scienc e B.V. All rights reserved.