PREDICTIONS OF FORMING LIMIT DIAGRAMS USING A RATE-DEPENT POLYCRYSTAL SELF-CONSISTENT PLASTICITY MODEL

J.W. SIGNORELLI; M.A. BERTINETTI; P.A. TURNER; R.E. BOLMARO

Belem

Congreso; 27th CILAMCE - Iberian Latin American Congress on Computational Methods in Engineering; 2006

A rate-dependent plasticity polycrystal self-consistent model and the Marciniak-Kuczynski (M-K) approach are applied to predict Forming Limit Diagrams (FLDs) of metal sheets. FLDs have been intensively studied, mostly based on the full-constraints Taylor model. The self-consistent approach is, to the authors’ knowledge, introduced for the first time in this work to simulate the polycrystal behavior. The effects on the FLDs of various factors characterizing the microstructure, topology and morphology of the material, are discussed: slip hardening, strain-rate sensitivity, initial imperfections and initial textures. Furthermore, the Viscoplastic Self-Consistent (VPSC) model has been used to discuss the effects of the ideal texture components (Cube {001}<100>, Goss {011}<100>, S {123}<634>, Brass {011}<211>) on the initiation of localized necking. The calculation with a more realistic scale transition successfully predicts some of the experimental tendencies which cannot be reproduce by conventional Taylor model