Prediction of the initial thickness of shear band localization based on a reduced strain gradient theory

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:48

Article

Chen, Shaohua¹  Feng, Biao¹  Wei, Yueguang¹  Wang, Tzuchiang¹ 

[1] Chinese Acad Sci, Inst Mech, LNM, Beijing 100190, Peoples R China

关键词: Shear band localization;    Thickness;    Tilt angle;    Strain gradient theory;   

DOI  :  10.1016/j.ijsolstr.2011.07.007

来源: Elsevier

【 摘 要 】

Plastic flow localization in ductile materials subjected to pure shear loading and uniaxial tension is investigated respectively in this paper using a reduced strain gradient theory, which consists of the couple-stress (CS) strain gradient theory proposed by Fleck and Hutchinson (1993) and the strain gradient hardening (softening) law (C-W) proposed by Chen and Wang (2000). Unlike the classical plasticity framework, the initial thickness of the shear band and the strain rate distribution in both cases are predicted analytically using a bifurcation analysis. It shows that the strain rate is obviously non-uniform inside the shear band and reaches a maximum at the center of the shear band. The initial thickness of the shear band depends on not only the material intrinsic length la but also the material constants, such as the yield strength, ultimate tension strength, the linear hardening and softening shear moduli. Specially, in the uniaxial tension case, the most possible tilt angle of shear band localization is consistent qualitatively with the existing experimental observations. The results in this paper should be useful for engineers to predict the details of material failures due to plastic flow localization. (C) 2011 Elsevier Ltd. All rights reserved.

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