Determination of the elastic modulus of microscale ceramic particles via nanoindentation

2004 ◽  
Vol 19 (8) ◽  
pp. 2437-2447 ◽  
Author(s):  
J.W. Leggoe
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Aluminum Matrix ◽  
Scalar Particle ◽  
Accurate Estimate ◽  
Flat Punch ◽  
Silicon Carbide Particles ◽  
Material Mismatch ◽  
Particulate Reinforced

Nanoindentation of the reinforcement in a particulate reinforced metal matrix composite (PR MMC) enables direct investigation of reinforcement properties within the finished material. Mismatch between the elastic moduli of the reinforcement and matrix creates a “secondary indentation” effect, whereby the stiffer reinforcement particles themselves “indent” the more compliant matrix. A finite-element investigation was undertaken to quantify the additional penetration arising under secondary indentation for spherical and cylindrical particles. Modification of Sneddon’s equation for a flat punch by a scalar particle shape factor provided an accurate estimate of the additional penetration. The modified equation was combined with the analysis of Field and Swain to extract the particle elastic modulus from results obtained using a spherical indenter under a multiple partial-unloading indentation regime. The resulting methodology was used to determine the elastic moduli of silicon carbide particles and MicralTM microspheres in two aluminum-matrix PR MMCs.

STATIC ELASTIC MODULUS OF THE TURKEY AORTA

1964 ◽  
Vol 42 (4) ◽  
pp. 553-562 ◽  
Author(s):  
Elwood W. Speckmann ◽  
Robert K. Ringer
Keyword(s):  
Blood Pressure ◽  
Elastic Modulus ◽  
Pressure Range ◽  
Elastic Moduli ◽  
Mature Male ◽  
Elevated Pressures ◽  
Arterial Blood ◽  
Blood Pressure Range ◽  
Thoracic And Abdominal

A method was described for the determination of the static elastic modulus for thoracic and abdominal aortas of the turkey. Love's equation was rearranged for calculation of the static elastic modulus as a function of volume. The elastic moduli of thoracic and abdominal aortas of untreated mature male Broad Breasted Bronze turkeys were in the neighborhood of 2.26 ± 0.11 and 9.55 ± 0.30 × 105 dynes/cm2 respectively in the normal physiological systolic blood pressure range. This difference became more pronounced at higher pressures. The data obtained support the concept that different connective tissue elements are primarily responsible for the elastic properties of arterial blood vessels at different pressure ranges. The addition of beta-amino-propionitrile (BAPN) to the ration tended to decrease, whereas the addition of ascorbic acid to the ration tended to elevate the elastic modulus. Reserpine fed in conjunction with BAPN in the ration did not correct the lowering action of BAPN on the elastic moduli of abdominal or thoracic aortas. Heat tended to elevate the elastic modulus of the aorta. Again, these effects became more significant at elevated pressures.

scholarly journals Determination of elastic moduli of elastic–plastic microspherical materials using nanoindentation simulation without mechanical polishing

2021 ◽  
Vol 12 ◽  
pp. 213-221
Author(s):  
Hongzhou Li ◽  
Jialian Chen
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Indentation Depth ◽  
Flat Surface ◽  
Computational Study ◽  
Experimental Methods ◽  
Mechanical Polishing ◽  
Initial Yield Stress ◽  
Elastic Plastic

When using the Oliver–Pharr method, the indented specimen is assumed to be a perfectly flat surface, thus ignoring the influences of surface roughness that might be encountered in experiment. For nanoindentation measurements, a flat surface is fabricated from curved specimens by mechanical polishing. However, the position of the polished curved surface cannot be controlled. There are no reliable theoretical or experimental methods to evaluate the mechanical behavior during nanoindentation of an elastic–plastic microsphere. Therefore, it is necessary to conduct reliable numerical simulations to evaluate this behavior. This article reports a systematic computational study regarding the instrumented nanoindentation of elastic–plastic microspherical materials. The ratio between elastic modulus of the microsphere and the initial yield stress of the microsphere was systematically varied from 10 to 1000 to cover the mechanical properties of most materials encountered in engineering. The simulated results indicate that contact height is unsuitable to replace contact depth for obtaining the indentation elastic modulus of microspherical materials. The extracted elastic modulus of a microsphere using the Oliver–Pharr method with the simulated unloading curve depends on the indentation depth. It demonstrates that nanoindentation on microspherical materials exhibits a “size effect”.

Nanoindentation of polydimethylsiloxane elastomers: Effect of crosslinking, work of adhesion, and fluid environment on elastic modulus

2005 ◽  
Vol 20 (10) ◽  
pp. 2820-2830 ◽  
Author(s):  
Fernando Carrillo ◽  
Shikha Gupta ◽  
Mehdi Balooch ◽  
Sally J. Marshall ◽  
Grayson W. Marshall ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Soft Materials ◽  
Work Of Adhesion ◽  
Aqueous Environment ◽  
Plastic Materials ◽  
Adhesion Contact ◽  
Fluid Environment ◽  
Micrometer Scale

With the potential to map mechanical properties of heterogeneous materials on a micrometer scale, there is growing interest in nanoindentation as a materials characterization technique. However, nanoindentation has been developed primarily for characterization of hard, elasto-plastic materials, and the technique has not been validated for very soft materials with moduli less than 5 MPa. The current study attempted to use nanoindentation to characterize the elastic moduli of soft, elastomeric polydimethylsiloxane (PDMS) samples (with different degrees of crosslinking) and determine the effects of adhesion on these measurements using adhesion contact mechanics models. Results indicate that nanoindentation was able to differentiate between elastic moduli on the order of hundreds of kilo-Pascals. Moreover, calculations using the classical Hertz contact model for dry and aqueous environment gave higher elastic modulus values when compared to those obtained from unconfined compression testing. These data seem to suggest that consideration of the adhesion energy at the tip-sample interface is a significantly important parameter and needs to be taken into account for consistent elastic modulus determination of soft materials by nanoindentation.

scholarly journals A novel method to determine the elastic modulus of extremely soft materials

Soft Matter ◽  
2015 ◽  
Vol 11 (21) ◽  
pp. 4180-4188
Author(s):  
Tamás Stirling ◽  
Miklós Zrínyi
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Soft Materials ◽  
Experimental Task ◽  
Novel Method

Determination of the elastic moduli of extremely soft materials that may deform under their own weight is a rather difficult experimental task.

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.

scholarly journals Uncertainty in the determination of elastic modulus by tensile testing

2021 ◽  
Author(s):  
Sonja Kostic ◽  
Jasmina Miljojkovic ◽  
Goran Simunovic ◽  
Djordje Vukelic ◽  
Branko Tadic
Keyword(s):  
Elastic Modulus ◽  
Tensile Testing

scholarly journals The Effects of Creep on Elastic Modulus Measurement Using Nanoindentation

2000 ◽  
Vol 649 ◽  
Author(s):  
G. Feng ◽  
A.H.W. Ngan
Keyword(s):  
Elastic Modulus ◽  
Elastic Deformation ◽  
Elastic Moduli ◽  
Holding Time ◽  
Time Dependent ◽  
Nanoindentation Test ◽  
Modification Method ◽  
Unloading Rate ◽  
Modulus Measurement

ABSTRACTDuring the unloading segment of nanoindentation, time dependent displacement (TDD) accompanies elastic deformation. Consequently the modulus calculated by the Oliver-Pharr scheme can be overestimated. In this paper we present evidences for the influence of the measured modulus by TDD. A modification method is also presented to correct for the effects of TDD by extrapolating the TDD law in the holding process to the beginning of the unloading process. Using this method, the appropriate holding time and unloading rate can be estimated for nanoindentation test to minimise the effects of TDD. The elastic moduli of three materials computed by the modification method are compared with the results without considering the TDD effects.

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