Numerical Evaluation of the Tool Wear Influence on Metal-Punching Processes.

Prediction of the influence of tool wear influence in sheet metal blanking/punching processes is investigated in this paper using the finite element method. In order to simulate accurately sheet metal-cutting processes by a material shearing mechanism, a finite element model valid for the numerical description of such processes has been developed. Damage and crack propagation has been taken into account by means of an elastoplastic constitutive law to study the effects of the variation of process parameters on the geometry of the sheared edges and the evolution of the force-punch penetration. Furthermore, a numerical investigation has been carried out to study the effect of tool wear on burr formation. During analysis, the initiation of a crack is assumed to occur, at any point in the sheet metal where the damage reaches a critical value. Crack propagation is simulated by the propagation of a completely damaged area. This is taken into account in the finite element model by a decrease of the stiffness of the broken elements. [ABSTRACT FROM AUTHOR]