Crystal Plasticity Simulation of Forming Limit Strains for Fcc Polycrystalline Sheets with Different r-values

Abstract

Plastic deformation characteristics and limit strains are simulated for textured face‐centered cubic polycrystalline sheets using a generalized Taylor‐type crystal plasticity model. The r‐values are predicted to be 1.04, 7.74 and 0.17 for the random, {111}〈uvw〉 and {001}〈uvw〉 textures, respectively. The {111}〈uvw〉 texture gives limit strains as large as the random texture, whereas the {001}〈uvw〉 texture yields limit strains evidently higher than the other two even though its r‐value is extremely low. Thus, the r‐value cannot act as an indicator to the stretchability of sheet metals. For the {001}〈uvw〉 texture, a superior strain‐hardening ability under plane‐strain stretching mode is found to be responsible for the increase in the limit strains under plane‐strain and equi‐biaxial stretching modes. We conclude that the enhancement of the strain‐hardening ability for plane strain mode is one of the key factors for high stretchability sheets.