Restraint model of draw bead and experimental investigation

The forming process of the metal sheet passing through drawbead in deep drawing is investigated. A simple and practical restraint model of drawbead is set up according to the energy principle. Furthermore a set of test devices with screw mechanism is designed and manufactured to test the drawbead restraint force. Aimed at various kinds of influence factors, tests are organized according to the orthogonal principle. It is shown that the drawbead restraint force is variable when the drawbead lies at arc position while it remains constant at line position during forming process; the theoretically computational values coincide with the test values well. The model can serve as the equivalent drawbead for the numerical simulations.