Indentation size effects in spherical nanoindentation analyzed by experiment and non-local crystal plasticity

Materialia ◽  
2018 ◽  
Vol 3 ◽  
pp. 21-30 ◽  
Author(s):  
J.K. Engels ◽  
S. Gao ◽  
W. Amin ◽  
A. Biswas ◽  
A. Kostka ◽  
...  
Keyword(s):  
Crystal Plasticity ◽  
Size Effects ◽  
Indentation Size ◽  
Non Local

A study of indentation work in homogeneous materials

2006 ◽  
Vol 21 (6) ◽  
pp. 1363-1374 ◽  
Author(s):  
Mengxi Tan
Keyword(s):  
Plastic Deformation ◽  
Elastic Modulus ◽  
Elastic Energy ◽  
Size Effects ◽  
Unit Volume ◽  
Plastic Work ◽  
Total Work ◽  
Indentation Size ◽  
Scaling Relationships ◽  
Homogeneous Materials

The work of indentation is investigated experimentally in this article. A method of using the elastic energy to extract the elastic modulus is proposed and verified. Two types of hardness related to the work of indentation are defined and examined: Hwtis defined as the total work required creating a unit volume of contact deformationand Hwp is defined as the plastic work required creating a unit volume of plastic deformation; experiments show that both hardness definitions are good choices for characterizing hardness. Several features that may provide significant insights in understanding indentation measurements are studied. These features mainly concern some scaling relationships in indentation measurements and the indentation size effects.

Investigation on dynamic hardness and high strain rate indentation size effects in aluminium (110) using nano-impact

2019 ◽  
Vol 133 ◽  
pp. 55-62 ◽  
Author(s):  
Liguang Qin ◽  
Heng Li ◽  
Xiangru Shi ◽  
Ben D. Beake ◽  
Lin Xiao ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Size Effects ◽  
High Strain ◽  
Indentation Size ◽  
Dynamic Hardness

On a Proper Account of First- and Second-Order Size Effects in Crystal Plasticity

2009 ◽  
Vol 11 (3) ◽  
pp. 143-147 ◽  
Author(s):  
Marc G. D. Geers ◽  
Ron H. J. Peerlings ◽  
Johan P. M. Hoefnagels ◽  
Yuriy Kasyanyuk
Keyword(s):  
Crystal Plasticity ◽  
Size Effects ◽  
Second Order ◽  
Proper Account

Length Scale Dependent Deformation in Polymers

2012 ◽  
Author(s):  
F. Alisafaei ◽  
Seyed Hamid Reza Sanei ◽  
Chung-Souk Han
Keyword(s):  
Liquid Crystal ◽  
Size Effects ◽  
Liquid Crystal Polymers ◽  
Length Scale ◽  
Indentation Testing ◽  
Indentation Size ◽  
Length Scales ◽  
Indentation Tests ◽  
Length Scale Dependent Deformation ◽  
Beam Bending

Length scale dependent deformation of polymers has been observed in different experiments including micro-beam bending and indentation tests. Here the length scale dependent deformation of polydimethylsiloxane is examined in indentation testing at length scales from microns down to hundreds of nanometers. Strong indentation size effects have been observed in these experiments which are rationalized with rotation gradients that can be related to Frank elasticity type molecular energies known from liquid crystal polymers. To support this notion additional experiments have been conducted where Berkovich and spherical indenter tips results have been compared with each other.

scholarly journals Upscaling and spatial localization of non-local energies with applications to crystal plasticity

2020 ◽  
pp. 108128652097324
Author(s):  
José Matias ◽  
Marco Morandotti ◽  
David R. Owen ◽  
Elvira Zappale
Keyword(s):  
Single Crystals ◽  
Crystal Plasticity ◽  
Weighting Function ◽  
Spatial Localization ◽  
Localization Formula ◽  
Weighted Averages ◽  
Structured Deformations ◽  
Energy Formula ◽  
Non Local

We describe multiscale geometrical changes via structured deformations [Formula: see text] and the non-local energetic response at a point x via a function [Formula: see text] of the weighted averages of the jumps [Formula: see text] of microlevel deformations [Formula: see text] at points y within a distance r of x. The deformations [Formula: see text] are chosen so that [Formula: see text] and [Formula: see text]. We provide conditions on [Formula: see text] under which the upscaling “[Formula: see text]” results in a macroscale energy that depends through [Formula: see text] on (1) the jumps [Formula: see text] of g and the “disarrangement field”[Formula: see text], (2) the “horizon” r, and (3) the weighting function [Formula: see text] for microlevel averaging of [Formula: see text]. We also study the upscaling “[Formula: see text]” followed by spatial localization “[Formula: see text]” and show that this succession of processes results in a purely local macroscale energy [Formula: see text] that depends through [Formula: see text] upon the jumps [Formula: see text] of g and the “disarrangement field”[Formula: see text] alone. In special settings, such macroscale energies [Formula: see text] have been shown to support the phenomena of yielding and hysteresis, and our results provide a broader setting for studying such yielding and hysteresis. As an illustration, we apply our results in the context of the plasticity of single crystals.

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