The Indentation and Puncture Properties of Rubber Vulcanizates

1961 ◽  
Vol 34 (3) ◽  
pp. 937-952 ◽  
Author(s):  
G. S. Yeh ◽  
D. I. Livingston
Keyword(s):  
Young’S Modulus ◽  
Satisfactory Agreement ◽  
Young's Modulus ◽  
Rubber Compound ◽  
Depth Of Penetration ◽  
Characteristic Relation ◽  
Puncture Strength

Abstract A detailed study has been made of the indentation and puncture properties of a number of rubber vulcanizates by a puncture method. It is shown that the characteristic relation between the force and depth of penetration, i.e., the two regions of linearity observed in a former study on a log-log plot, can be represented by two equations. The first region, in which the indenter penetrates into the rubber to a depth approximately equal to twice its diameter, can be generally described by Timoshenko's classical relation, FI=2.67 Erd In the second region, an empirically derived equation FII=1.34 Er0.5d1.5 holds. For a given rubber compound, Young's modulus calculated from the second equation is in satisfactory agreement with the modulus obtained from the first. The puncture strength and the puncture depth are both shown to be dependent upon the compounding variations and they provide useful information about the vulcanizates such as stiffness and cure. Valuable information relating to rubber abrasion and road wear may also result from studies of these two puncture properties.

The Strain Dependence of Rubber Viscoelasticity. II. The Influence of Carbon Black

1962 ◽  
Vol 35 (4) ◽  
pp. 918-926 ◽  
Author(s):  
P. Mason
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Particle Diameter ◽  
Viscoelastic Behavior ◽  
Spherical Particles ◽  
Rubber Compound ◽  
Similar Treatment ◽  
Linear Relations ◽  
The Individual ◽  
Individual Particles

Abstract In Part I of this series it was shown how variations in the dynamic Young's modulus with extension could be represented by linear relations for gum rubbers in the region of 0 to 100% extension. The present work uses a similar treatment to examine how the viscoelastic behavior of natural rubber within this extension region is affected by the incorporation of two carbon blacks of widely differing colloidal activity. One of these materials, MT black, consists substantially of spherical particles with a mean diameter of about 0.4 microns: electron microscopy of cut surfaces of the black-rubber compound showed that the individual particles were well-dispersed. The finer material, HAF black, has a mean particle diameter of about 0.04 microns but exists in the rubber compound in a flocculated condition with aggregates up to about 0.3 microns in diameter. The rubber containing the coarse, MT black yielded linear strain relations enabling a direct comparison to be made with the behavior of the gum: the HAF material did not give linear relations for either the dynamic or the equilibrium Young's modulus. To facilitate discussion of this behavior it is desirable to set out more explicitly than in Part I the model underlying the analysis.

Determination of the hardness and young's modulus from the depth of penetration of a pyramidal indentor

1983 ◽  
Vol 15 (11) ◽  
pp. 1624-1628 ◽  
Author(s):  
B. A. Galanov ◽  
O. N. Grigor'ev ◽  
Yu. V. Mil'man ◽  
I. P. Ragozin
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Depth Of Penetration

Continuous measurements of load-penetration curves with spherical microindenters and the estimation of mechanical properties

1998 ◽  
Vol 13 (5) ◽  
pp. 1390-1400 ◽  
Author(s):  
J. Alcalá ◽  
A. E. Giannakopoulos ◽  
S. Suresh
Keyword(s):  
Young’S Modulus ◽  
Large Scale ◽  
Young's Modulus ◽  
Accurate Determination ◽  
Elastic Response ◽  
Small Scale ◽  
Depth Of Penetration ◽  
Plastic Properties ◽  
Continuous Measurements ◽  
Contact Response

Elastic and plastic properties of metals and Young's modulus of ceramics are determined in the microindentation regime by continuous measurements of load versus depth of penetration with spherical indenters. Calibration procedures, usually applied in nanoindentation experiments, are not needed in the microregime where spherical indenters (rather than sharp indenters with microscopical spherical tips) can be manufactured. As indenters of larger diameters are used, the elastic response of the specimen can be probed during the loading stage of the indentation tests (and not only during unloading, as is the case with nanoindenters). Hence, an accurate determination of Young's modulus can be achieved without a prior knowledge of possible “piling up” or “sinking in” which may occur at the perimeter of the contact area. The contact response of materials is shown to undergo four distinct regions: (i) pre-Hertzian regime, (ii) Hertzian regime, (iii) small-scale plasticity, and (iv) large-scale plasticity. A general methodology for estimation of yield strength and hardening exponent of metals is proposed in the last regime.

Contact Elasticity of Seal Elastomers

1968 ◽  
Vol 90 (2) ◽  
pp. 478-483 ◽  
Author(s):  
R. C. Drutowski
Keyword(s):  
Young’S Modulus ◽  
Experimental Work ◽  
Optical Measurement ◽  
Young's Modulus ◽  
Contact Analysis ◽  
Hertzian Contact ◽  
Depth Of Penetration ◽  
Critical Comparison ◽  
Hardness Tests ◽  
Work Done

The calculation of Young’s modulus of an elastomer is based on the optical measurement of the contact between a transparent spherical indenter and the elastomer. The technique is based on Hertzian contact analysis and agrees with the work done by others on the depth of penetration of indenters. A critical comparison of this method is made with conventional hardness tests. Experimental work establishes the fact that determinations of Young’s modulus based on indentations in thin samples are permissible only if the strains in the elastomer are kept below a calculable limit. The dependence of elastomer modulus on prior strain is described and fluid-elastomer interactions are examined in detail.

Load-compression relationships of rubber units

1966 ◽  
Vol 1 (3) ◽  
pp. 190-195 ◽  
Author(s):  
P. B. Lindley
Keyword(s):  
Young’S Modulus ◽  
Satisfactory Agreement ◽  
Young's Modulus ◽  
Experimental Measurements ◽  
Small Strains ◽  
Compression Characteristics

A theory, based on a strain-independent Young's modulus and a previously developed theory for the compression of bonded rubber blocks at small strains, is proposed to account for the load-compression characteristics of rubber units at high strains. Theoretical relationships for rubber blocks, toroidal rings, spheres and rubber-covered rollers are developed and shown to be in satisfactory agreement with experimental measurements.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

Degradation of Rocks, Through Cracking Caused by Differential Thermal Expansion, in Relation to Nuclear Waste Repositories

1981 ◽  
Vol 6 ◽  
Author(s):  
J.R. Mclaren ◽  
R.W. Davidge ◽  
I. Titchell ◽  
K. Sincock ◽  
A. Bromley
Keyword(s):  
Thermal Expansion ◽  
Grain Boundary ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Crack Density ◽  
Granitic Rocks ◽  
Multiphase Materials ◽  
Thermal Expansion Behaviour ◽  
Waste Repositories ◽  
Expansion Behaviour

ABSTRACTHeating to temperatures up to 500°C, gives a reduction in Young's modulus and increase in permeability of granitic rocks and it is likely that a major reason is grain boundary cracking. The cracking of grain boundary facets in polycrystalline multiphase materials showing anisotropic thermal expansion behaviour is controlled by several microstructural factors in addition to the intrinsic thermal and elastic properties. Of specific interest are the relative orientations of the two grains meeting at the facet, and the size of the facet; these factors thus introduce two statistical aspects to the problem and these are introduced to give quantitative data on crack density versus temperature. The theory is compared with experimental measurements of Young's modulus and permeability for various rocks as a function of temperature. There is good qualitative agreement, and the additional (mainly microstructural) data required for a quantitative comparison are defined.

Is it necessary to calculate Young’s modulus in AFM nanoindentation experiments regarding biological samples?

2020 ◽  
Vol 12 ◽  
Author(s):  
S.V. Kontomaris ◽  
A. Malamou ◽  
A. Stylianou
Keyword(s):  
Young’S Modulus ◽  
Biological Samples ◽  
Young's Modulus ◽  
Reference Sample ◽  
Nonlinear Behavior ◽  
Accurate Method ◽  
Accurate Solution ◽  
Hertz Model ◽  
Work Done

Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require very heavy workload and highly specialized personnel. Objective: In this paper a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for the mechanical characterization at the nanoscale. Method: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters. Results: The proposed approach, not only provides an accurate solution from a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip. Conclusion: The proposed, by this opinion paper, solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.

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