Determination of fracture criteria during the deep drawing of conical cups

In consideration of the effects of factors such as the tool geometry, material anisotropy and working–hardening, the fracture criteria, which are expressed by the equations of limit stress and limit load during conical cup drawing, are formulated theoretically based on the stress–strain states on the critical section of fracture using Swift’s instability criterion, and they 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.