An incremental flow theory for crystal plasticity incorporating strain gradient effects

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:110

Article

Nellemann, C.¹  Niordson, C. F.¹  Nielsen, K. L.¹ 

[1] Tech Univ Denmark, Dept Mech Engn, Solid Mech, DK-2800 Lyngby, Denmark

关键词: Higher order theory;    Size effects;    Rate-independent formulation;   

DOI  :  10.1016/j.ijsolstr.2017.01.025

来源: Elsevier

【 摘 要 】

The present work investigates a new approach to formulating a rate-independent strain gradient theory for crystal plasticity. The approach takes as offset recent discussions published in the literature for isotropic plasticity, and a key ingredient of the present work is the manner in which a gradient enhanced effective slip measure governs hardening evolution. The effect of both plastic strains and plastic strain gradients are combined into this scalar effective slip quantity, the energy associated with plastic strain is dissipative (unrecoverable), while the energy from plastic strain gradients is recoverable (free). The framework developed forms the basis of a finite element implementation and is demonstrated on benchmark problems designed to bring out effects such as strengthening and hardening. Monotonic loading and plane strain deformation is assumed throughout, but despite this, non-proportidnal straining is predicted in the plastic regime even under pure shear conditions. Results of single slip and symmetric double slip reveal that strengthening and hardening are governed by the slip system orientation and the material length parameter only. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

Free