Simulation of Torsion of Thin FCC Single Crystal Wires by Mechanism-Based Strain Gradient Crystal Plasticity

Abstract:

The size effects observed in the torsion of thin FCC single crystal wires is modelled by the employment of mechanism-based strain gradient crystal plasticity (MSG-CP). In the formulation the total slip resistance in each active slip system is assumed to be due to a mixed population of forest obstacles arising from both statistically stored and geometrically necessary dislocations. The MSG-CP constitutive model is implemented into the Abaqus/Standard FE platform by developing the User MATerial subroutine UMAT. By implementing the formulation, the relationship between the non-dimensional torque and the surface strain of the thin copper single crystal wires of different diameters is obtained with the [001] direction along that of the wire axis. The simulation results of torsion reveal size effects, which is in a qualitative agreement with those reported in existing literatures. An appreciable axial elongation is also found in the torsion of single crystal wires.Key words Size effect, MSG-CP model, Torsion

• Periodical: Key Engineering Materials (Volume 626)
• Pages: 139-144
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.626.139
• Online since: August 2014
• Authors: Yi Ping Chen*, Ying Ying Cai, Q. Ni, G.Y. Zhao
• Keywords: MSG-CP Model, Size Effect, Torsion

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