Determination of fracture criteria during the deep drawing of conical cups

In consideration of the effects of factors such as the tool geometry, mater ial anisotropy and working-hardening, the fracture criteria, which are expr essed by the equations of limit stress and limit load during conical cup dr awing, are formulated theoretically based on the stress-strain starts on th e critical section of fracture using Swift's instability criterion, and the y are proven experimentally to be accurate. Therefore, they can be used for judging whether the process can form successfully and for determining the limit deformation of conical cups. (C) 2001 Elsevier Science B.V. All right s reserved.