Finite–element analysis as a tool for the investigation of the mechanics of wire drawing

Wistreich's classical experiments where friction in Cu wire–drawing was determined from a combined measurement of were reproduced in a FE–analysis. There was good correspondence between Wistreich's experimental data and the m–computed results when friction was modelled as Coulomb friction. The dependence of the contact stresses transferred from the wire to the die, and the coefficient of friction, on different drawing parameters was analysed. It seems as if the friction between the die and the wire depends on the geometry of the wire inside the drawing cone, through its A–parameter, i.e. the height–to–length ratio of the wire inside this cone. The mean die pressure was found to increase linearly with increasing A–parameter. The mean shear stress transferred from the wire to the die was also found to increase linearly with this parameter. As a consequence of this the Coulomb coefficient of friction would increase in a parabolic manner with the A–parameter.