A theory for grain boundaries with strain-gradient plasticity

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:51

Article

Voyiadjis, George Z.¹  Faghihi, Danial¹  Zhang, Yida² 

[1] Louisiana State Univ, Dept Civil & Environm Engn, Baton Rouge, LA 70803 USA

[2] Northwestern Univ, Dept Civil & Environm Engn, Evanston, IL 60201 USA

关键词: Grain boundaries;    Gradient plasticity;    Nanoindentation;    Heat generation due to plastic work;   

DOI  :  10.1016/j.ijsolstr.2014.01.020

来源: Elsevier

【 摘 要 】

In this work, the effect of the material microstructural interface between two materials (i.e., grain boundary in polycrystalls) is adopted into a thermodynamic-based higher order strain gradient plasticity framework. The developed grain boundary flow rule accounts for the energy storage at the grain boundary due to the dislocation pile up as well as energy dissipation caused by the dislocation transfer through the grain boundary. The theory is developed based on the decomposition of the thermodynamic conjugate forces into energetic and dissipative counterparts which provides the constitutive equations to have both energetic and dissipative gradient length scales for the grain and grain boundary. The numerical solution for the proposed framework is also presented here within the finite element context. The material parameters of the gradient framework are also calibrated using an extensive set of micro-scale experimental measurements of thin metal films over a wide range of size and temperature of the samples. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

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