scholarly journals Determination of mechanical properties by nanoindentation independently of indentation depth measurement

2012 ◽  
Vol 27 (19) ◽  
pp. 2551-2560 ◽  
Author(s):  
Gaylord Guillonneau ◽  
Guillaume Kermouche ◽  
Sandrine Bec ◽  
Jean-Luc Loubet
Keyword(s):  
Mechanical Properties ◽  
Indentation Depth ◽  
Depth Measurement ◽  
Image Position

Abstract

scholarly journals Determination of the Mechanical Properties of PIN–PMN–PT Bulk Single Crystals by Nanoindentation

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Fengchao Lang ◽  
Chunwang Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Single Crystals ◽  
Indentation Depth ◽  
Young’S Moduli ◽  
Indentation Process ◽  
Maximum Indentation Depth ◽  
Elastic And Plastic Deformations ◽  
Bulk Single Crystals

The present study aimed to experimentally evaluate the mechanical properties of Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) bulk single crystals with different crystallographic directions using the nanoindentation technique. The load–indentation depth curves, elastic and plastic deformations, hardnesses, and Young’s moduli of [100]- and [110]-oriented 0.28PIN–0.43PMN–0.29PT bulk single crystals were investigated. Our results show that with an increase in the maximum indentation depth hmax, the plastic residual percentage increased for both the [100]- and the [110]-oriented single crystals. At each hmax, the plastic residual percentage of the [100]-oriented PIN–PMN–PT single crystals was less than that of the [110]-oriented PIN–PMN–PT single crystals. At hmax from 500 nm to 2000 nm, the plastic deformation was larger than the elastic deformation, and the plastic residual percentage was larger than 50% for both the [100]- and the [110]-oriented single crystals. This means that the plastic deformation dominated in the indentation process of PIN–PMN–PT single crystals. The indentation size effect on the hardness of the PIN–PMN–PT single crystals was apparent in the nanoindentation process. Both the hardness and the Young’s modulus of the [100]-PIN–PMN–PT single crystals were greater than those of the [110]-PIN–PMN–PT single crystals, which indicates that the PIN–PMN–PT single crystals had anisotropic mechanical characteristics.

EFFECT OF MECHANICAL PROPERTIES OF THE SUBSTRATE TISSUES ON THE DETERMINATION OF ELASTIC MODULUS OF THE SCLERA USING INDENTATION TEST

2016 ◽  
Vol 16 (07) ◽  
pp. 1650085
Author(s):  
XIUQING QIAN ◽  
KUNYA ZHANG ◽  
ZHICHENG LIU
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Elastic Modulus ◽  
Elastic Moduli ◽  
Indentation Depth ◽  
Vitreous Body ◽  
Indentation Test ◽  
Posterior Pole

The sclera is an important connective tissue that protects the sensitive layers within the eyeball. Identifying the mechanical properties of the sclera near the posterior pole is necessary to analyze the deformation of the sclera and stresses changing in the optic nerve head tissues. We propose a method to determine the mechanical properties of the sclera using dimensional analysis, finite element method and the indentation test. The elastic moduli of the sclera for different indentation depths and positions were identified. We found that the elastic moduli of the sclera varied with indentation depth. This was due to the effect of the mechanical properties of the substrate tissues inside the sclera. The elastic modulus of the choroid had the biggest effect on the determination of elastic modulus of the sclera, whereas that of the vitreous body could be ignored when the ratio of the indentation depth to the thickness of the sclera was less than 0.5. The effects of mechanical properties of the substrate tissues become more pronounced at greater indentation depths.

Indenter Tip Dependence in the Determination of Elastic Modulus in Polymers

2013 ◽  
Author(s):  
Seyed Hamid Reza Sanei ◽  
F. Alisafaei ◽  
Chung-Souk Han
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Elastic Modulus ◽  
Indentation Depth ◽  
Length Scale ◽  
Berkovich Indenter ◽  
Thin Wires ◽  
Length Scale Dependent Deformation ◽  
Nanoindentation Experiment

The two most common outputs of nanoindentation experiment are hardness and elastic modulus. Length scale dependent deformation in polymers has however been observed in different experiments such as microbeam bending, torsional thin wires and indentation testing which may affect the mechanical testing. Unlike in metals where the size dependency is attributed to necessary geometry dislocations, the origin of length scale dependent deformation in polymers is not well understood. In this study, elastic modulus of polydimethylsiloxane (PDMS) is determined using both Berkovich and spherical tips. Observing different trends for elastic modulus upon the change of indentation depth using these two different tips brings up the question which tip should be used to get the real mechanical properties of PDMS which is discussed here. Surface roughness, surface effects and the imperfection of the Berkovich indenter tip are negligible at the studied length scale.

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

Sign in / Sign up

Export Citation Format

Share Document