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Title: Influences of stress on the measurement of mechanical properties using nanoindentation: Part II. Finite element simulations

Abstract

The finite element method has been used to study the behavior of aluminum alloy 8009 during elastic-plastic indentation to establish how the indentation process is influenced by applied or residual stress. The study was motivated by the experiments of the preceding paper which show that nanoindentation data analysis procedures underestimate indentation contact areas and therefore overestimate hardness and elastic modulus in stressed specimens. The NIKE2D finite element code was used to simulate indentation contact by a rigid, conical indenter in a cylindrical specimen to which biaxial stresses were applied as boundary conditions. Indentation load-displacement curves were generated and analyzed according to standard methods for determining hardness and elastic modulus. The simulations show that the properties measured in this way are inaccurate because pileup is not accounted for in the contact area determination. When the proper contact area is used, the hardness and elastic modulus are not significantly affected by the applied stress. {copyright} {ital 1996 Materials Research Society.}

Authors:
 [1];  [2];  [1]
  1. Department of Materials Science, Rice University, 6100 Main Street, Houston, Texas 77005 (United States)
  2. Nano Instruments, Inc., 1001 Larson Drive, Oak Ridge, Tennessee 37830 (United States)
Publication Date:
Research Org.:
Oak Ridge Institute of Science and Education
Sponsoring Org.:
USDOE
OSTI Identifier:
282840
DOE Contract Number:  
AC05-76OR00033; AC05-84OR21400
Resource Type:
Journal Article
Journal Name:
Journal of Materials Research
Additional Journal Information:
Journal Volume: 11; Journal Issue: 3; Other Information: PBD: Mar 1996
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; MECHANICAL PROPERTIES; MEASURING METHODS; COMPUTERIZED SIMULATION; FINITE ELEMENT METHOD; STRESSES; INDENTATION

Citation Formats

Bolshakov, A, Oliver, W C, and Pharr, G M. Influences of stress on the measurement of mechanical properties using nanoindentation: Part II. Finite element simulations. United States: N. p., 1996. Web. doi:10.1557/JMR.1996.0092.
Bolshakov, A, Oliver, W C, & Pharr, G M. Influences of stress on the measurement of mechanical properties using nanoindentation: Part II. Finite element simulations. United States. doi:10.1557/JMR.1996.0092.
Bolshakov, A, Oliver, W C, and Pharr, G M. Fri . "Influences of stress on the measurement of mechanical properties using nanoindentation: Part II. Finite element simulations". United States. doi:10.1557/JMR.1996.0092.
@article{osti_282840,
title = {Influences of stress on the measurement of mechanical properties using nanoindentation: Part II. Finite element simulations},
author = {Bolshakov, A and Oliver, W C and Pharr, G M},
abstractNote = {The finite element method has been used to study the behavior of aluminum alloy 8009 during elastic-plastic indentation to establish how the indentation process is influenced by applied or residual stress. The study was motivated by the experiments of the preceding paper which show that nanoindentation data analysis procedures underestimate indentation contact areas and therefore overestimate hardness and elastic modulus in stressed specimens. The NIKE2D finite element code was used to simulate indentation contact by a rigid, conical indenter in a cylindrical specimen to which biaxial stresses were applied as boundary conditions. Indentation load-displacement curves were generated and analyzed according to standard methods for determining hardness and elastic modulus. The simulations show that the properties measured in this way are inaccurate because pileup is not accounted for in the contact area determination. When the proper contact area is used, the hardness and elastic modulus are not significantly affected by the applied stress. {copyright} {ital 1996 Materials Research Society.}},
doi = {10.1557/JMR.1996.0092},
journal = {Journal of Materials Research},
number = 3,
volume = 11,
place = {United States},
year = {1996},
month = {3}
}