Finite Element studies on indentation size effect using a higher order strain gradient theory

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:50

Article

Guha, Suman¹  Sangal, Sandeep¹  Basu, Sumit² 

[1] Indian Inst Technol, Dept Mat Sci & Engn, Kanpur 208016, Uttar Pradesh, India

[2] Indian Inst Technol, Dept Mech Engn, Kanpur 208016, Uttar Pradesh, India

关键词: Micro-indentation;    Strain gradient viscoplasticity;    Finite Element method;   

DOI  :  10.1016/j.ijsolstr.2012.10.017

来源: Elsevier

【 摘 要 】

In this work, a Finite Element implementation of a higher order strain gradient theory (due to Fleck and Hutchinson, 2001) has been used within the framework of large deformation elasto-viscoplasticity to study the indentation of metals with indenters of various geometries. Of particular interest is the indentation size effect (ISE) commonly observed in experiments where the hardness of a range of materials is found to be significantly higher at small depths of indentation but reduce to a lower, constant value at larger depths. That the ISE can be explained by strain gradient plasticity is well known but this work aims to qualitatively compare a gamut of experimental observations on this effect with predictions from a higher order strain gradient theory. Results indicate that many of the experimental observations are qualitatively borne out by our simulations. However, areas exist where conflicting experimental results make assessment of numerical predictions difficult. (C) 2012 Elsevier Ltd. All rights reserved.

【 授权许可】

Free