ANALYSIS OF 3-DIMENSIONAL HEXAGONAL CLOSED-DIE HEADING BY THE FINITE-ELEMENT FLOW FORMULATION

Modelling three-dimensional metal-forming processes with the finite-el ement flow formulation based on the Doraivelu et al. constitutive equa tions is considered. The basic theory is reviewed. Special emphasis is placed on the numerical implementation of such formulation. The autho rs discuss the substitution of the Gauss by the Irons numerical integr ation rule for the evaluation of the deviatoric component of the gener alized stiffness matrix, and present two criteria for analysing mesh d egeneracy and mesh die interference. Three-dimensional contact problem s are discussed briefly. Three-dimensional closed-die hexagonal headin g, starting from a cylindrical aluminium-alloy billet, is reported. Th eoretical and experimental results for the punch load punch displaceme nt evolution are analysed, good agreement between them being found.