PRODUCT THICKNESS ANALYSIS IN PURE CUP-DRAWING

An analytical model is developed to estimate the variation of wall thi ckness of a drawn cup in a pure bending-drawing process, the model inc luding both non-linear strain-hardening and frictional force between b lank and die. The theoretical prediction of cup wall thickness is in a greement with the results of experimental measurement. The reduction o f the friction coefficient between the blank and the tooling surfaces reduces the stretching effect and the thinning of the wall of the cup, conversely a high value of the friction coefficient and high strain-h ardening enhancing the stretching effect and thickness reduction, part icularly at the outside edge. The validity of the theoretical analysis has been investigated by experiment, the theoretical prediction of th e variation in the wall thickness of the cup being in agreement with t he results of experimental measurement.