Modelagem não linear de elementos finitos do processo de trefilação incluindo fricção

Abstract

Wire drawing is commonly used in industry, mainly for the mass fabrication of wires and rods. It couples production efficiency with a good superficial quality of the final product and it provides an increase of the material strength through the plastic straining during the metal cold forming. The numerical work presented here focuses on the finite element simulation of the real life wire drawing procedure implemented at a metal working factory. The main motivations of the work are a deeper understanding of the wire drawing procedure and the future prediction of the wire drawing parameters and product quality as a function of the material properties of the raw material measured on site. A pre-existing nonlinear model, using the finite element method, was adapted to better understand the wire drawing process, identifying the dominating parameters. The finite element model includes the following nonlinear ingredients: contact/friction treatment through the augmented Lagrangian method, co-rotacional finite strain formulation, elastic-(visco)plastic material behavior with isotropic nonlinear hardening. It uses an axisymmetric modeling assumption, considering the cylindrical shape of the work piece. This model allows for observing in details the phenomena occurring during the wire drawing and it is used for a computational investigation of the wire drawing parameters (friction between die and work piece, die semi-angle, material properties, etc) and their influences.