G. M. Castelluccio, Sandia National Laboratories, NM, USA

Mesoscale-SENSITIVE crystal plasticity
When Jun 23, 2016
from 02:00 PM to 03:00 PM
Where LR8
Contact Name
Contact Phone 01865-273184
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Constitutive formulations have increasingly focused on physically-based approaches that are less phenomenological but incorporate information from multiple scales. Most dislocation-based plasticity approaches reflect homogeneous many-body dislocation physics without considering the length scales introduced by the localization of dislocation densities. These mesoscopic length scales have a critical intermediary role between the effective and real stress at micro- and nano-scales. This work presents a crystal plasticity framework that explicitly incorporates length-scales and evolution laws associated with mesoscale structures such as cells and persistent slip bands in metallic materials under cyclic loading. The formulation is based on Eshelby inclusion approach and demonstrates that the back stress can be originated by localization of dislocations into wall structures. The results show agreement between models and experiments for a wide range of strains without introducing artificial fitting coefficients.