Analysis Of Dynamic Shear Bands In An FCC Single Crystal

Abstract

We study plane strain dynamic thermomechanical deformations of an fcc single crystal compressed along the crystallographic direction [010] at an average strain rate of 1000 sec-1. Two cases are studied; one in which the plane of deformation is parallel tothe plane (001) of the single crystal, and another one with deformation occuring in the plane (101̄) of the single crystal. In each case, the 12 slip systems are aligned symmetrically about the two centroidal axes. We assume that the elastic and plastic deformations of the crystal are symmetrical about these two axes. The crystal material is presumed to exhibit strain hardening, strain-rate hardening, and thermal softening. A simple combined isotropic-kinematic hardening expression for the critical resolved shear stress, proposed by Weng, is modified to account for the affine thermal softening of the material. When the deformation is in the plane (001) of the single crystal, four slip systems (111)[11̄0], (111̄)[11̄0], (11̄;1̄;)[110], and (11̄1)[110] are active in the sense that significant plastic deformations occur along these slip systems. However, when the plane of deformation is parallel to the plane (101̄;) of the single crystal, slip systems (11̄;1)[110], (11̄1)[011], (111)[11̄0], and (111)[01̄1] are more active than the other eight slip systems. At an average strain of 0.0108, the maximum angle of rotation of a slip system within a shear band, about an axis perpendicular to the plane of deformation, is found to be 20.3° in the former case, and 22.9° in the latter. © 1993.

Department(s)

Mechanical and Aerospace Engineering

Comments

National Science Foundation, Grant DAAL03-91-G-0084

International Standard Serial Number (ISSN)

0749-6419

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

01 Jan 1993

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