Determination of the elastic properties of glasses and polymers exploiting the resonant characteristic of depth-sensing indentation tests

2001 ◽  
Vol 16 (6) ◽  
pp. 1776-1783 ◽  
Author(s):  
D. Lorenz ◽  
W. Fränzel ◽  
M. Einax ◽  
P. Grau ◽  
G. Berg
Keyword(s):  
Young’S Modulus ◽  
Closed Loop ◽  
Young's Modulus ◽  
Elastic Recovery ◽  
Indentation Test ◽  
Material Behavior ◽  
New Method ◽  
Depth Sensing ◽  
Constant Frequency ◽  
Indentation Tests

Depth-sensing indentation tests can be used to estimate the Young's modulus, hardness, and other characteristics of material behavior. For many materials, the unloading segment of the load–depth curve contains only elastic recovery while the loading segment can contain elastic and plastic deformation. In this paper a new method is presented to determine the Young's modulus of a material from the loading segment of an indentation test. A depth-sensitive hardness tester was used with a load cell integrated into the closed-loop system. Defined mechanical oscillations with constant frequency were generated by adding a piezoelectric stack to the closed loop of the hardness measurement system. Thus the resonance response of the system was obtained, which includes information regarding the stiffness of the tested material. This new method was tested on two polymers and two glasses, an optical and a conventional one. The results obtained for the Young's modulus were in good agreement with other accepted methods.

scholarly journals Analysis of depth-sensing indentation tests with a Knoop indenter

2001 ◽  
Vol 16 (6) ◽  
pp. 1660-1667 ◽  
Author(s):  
L. Riester ◽  
T. J. Bell ◽  
A. C. Fischer-Cripps
Keyword(s):  
Elastic Modulus ◽  
Elastic Recovery ◽  
Indentation Test ◽  
New Method ◽  
Short Axis ◽  
Depth Sensing ◽  
Specimen Material ◽  
Indentation Tests ◽  
Conventional Methods ◽  
Knoop Indenter

The present work shows how data obtained in a depth-sensing indentation test using a Knoop indenter may be analyzed to provide elastic modulus and hardness of the specimen material. The method takes into account the elastic recovery along the direction of the short axis of the residual impression as the indenter is removed. If elastic recovery is not accounted for, the elastic modulus and hardness are overestimated by an amount that depends on the ratio of E/H of the specimen material. The new method of analysis expresses the elastic recovery of the short diagonal of the residual impression into an equivalent face angle for one side of the Knoop indenter. Conventional methods of analysis using this corrected angle provide results for modulus and hardness that are consistent with those obtained with other types of indenters.

A New Method Developed for Brittle and Ductile Materials to Evaluate Mechanical Properties of a Lump Specimen in the Use of Indentation Test

2006 ◽  
Vol 129 (2) ◽  
pp. 284-292 ◽  
Author(s):  
Pal Jen Wei ◽  
Jen Fin Lin
Keyword(s):  
Yield Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Elastic Recovery ◽  
Indentation Test ◽  
New Method ◽  
Ductile Materials ◽  
Conventional Material ◽  
Loading And Unloading ◽  
Logarithm Function

In this study, the load-depth (P‐h) relationships matching the experimental results of the nanoindentation tests exhibited at the subregions of small and large depths are obtained, respectively. The relationships associated with these two subregions are then linked by the hyperbolic logarithm function to attain a single expression that is applied in the evaluation of the specimen’s elastic recovery ability, as shown in the unloading process. A new method is developed in the present study to evaluate both Young’s modulus and the yield strength of either a ductile or brittle material through the uses of the appropriate P‐h relationships developed in the load and unloading processes. The results of the Young’s modulus and the yield strength achieved by the present method are compared to those obtained from the conventional material tests for a lump material. The scattering of the experimental data shown in the loading and unloading processes are also interpreted by different causes.

Elastic constants of trapped lung parenchyma

1978 ◽  
Vol 44 (6) ◽  
pp. 853-858 ◽  
Author(s):  
S. J. Lai-Fook ◽  
R. E. Hyatt ◽  
J. R. Rodarte
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Young's Modulus ◽  
Indentation Test ◽  
Lung Parenchyma ◽  
Accurate Estimate ◽  
The Other ◽  
Indentation Tests ◽  
Trapped Lung

Isolated dog lobes were maximally trapped with air, and their parenchymal elastic properties were measured at the trapped volume. Indentation tests were performed on the surface of the lobes, followed by uniaxial and torsion tests on excised pieces of parenchyma. Similar values for Young's modulus were obtained from the indentation and uniaxial tests. The values for the shear modulus from the torison tests also were consistent with Young's modulus measured by the other procedures. The indentation test provided an accurate estimate of Young's modulus or the shear modulus for trapped lobes, and the results suggest that it is a valid method for estimating these constants in nontrapped lobes.

scholarly journals Hardness, Young’s Modulus and Elastic Recovery in Magnetron Sputtered Amorphous AlMgB14 Films

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 823
Author(s):  
Alexander M. Grishin
Keyword(s):  
Young’S Modulus ◽  
Indentation Size Effect ◽  
Young's Modulus ◽  
Elastic Recovery ◽  
Rf Power ◽  
Magnesium Boride ◽  
Wide Range ◽  
Aluminum Magnesium Boride ◽  
Optical And Mechanical Properties ◽  
Diamond Probe

We report optical and mechanical properties of hard aluminum magnesium boride films magnetron sputtered from a stoichiometric AlMgB14 ceramic target onto Corning® 1737 Glass and Si (100) wafers. High target sputtering rf-power and sufficiently short target-to-substrate distance appeared to be critical processing conditions. Amorphous AlMgB14 films demonstrate very strong indentation size effect (ISE): exceptionally high nanohardness H = 88 GPa and elastic Young’s modulus E* = 517 GPa at 26 nm of the diamond probe penetration depth and almost constant values, respectively, of about 35 GPa and 275 GPa starting at depths of about 2–3% of films’ thickness. For comparative analysis of elastic strain to failure index  H/E*, resistance to plastic deformation ratio H3/E*2 and elastic recovery ratio We were obtained in nanoindentation tests performed in a wide range of loading forces from 0.5 to 40 mN. High authentic numerical values of H = 50 GPa and E* = 340 GPa correlate with as low as only 10% of total energy dissipating through the plastic deformations.

A new method of measuring the Young’s modulus in a paper cone

1996 ◽  
Vol 99 (4) ◽  
pp. 2183-2187 ◽  
Author(s):  
Qing‐Tian Tao ◽  
Zhi‐Liang Zhang
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
New Method

A Phenomenological Model for the Hysteresis Behavior of Metal Sheets Subjected to Unloading/Reloading Cycles

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
P.-A. Eggertsen ◽  
K. Mattiasson ◽  
J. Hertzman
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Elastic Recovery ◽  
Yield Criterion ◽  
Experimental Investigations ◽  
Secant Modulus ◽  
New Model ◽  
Forming Simulation ◽  
Metal Sheets ◽  
Steel Grades

The springback phenomenon is defined as elastic recovery of the stresses produced during the forming of a material. An accurate prediction of the springback puts high demands on the material modeling during the forming simulation, as well as during the unloading simulation. In classic plasticity theory, the unloading of a material after plastic deformation is assumed to be linearly elastic with the stiffness equal to Young’s modulus. However, several experimental investigations have revealed that this is an incorrect assumption. The unloading and reloading stress–strain curves are in fact not even linear, but slightly curved, and the secant modulus of this nonlinear curve deviates from the initial Young’s modulus. More precisely, the secant modulus is degraded with increased plastic straining of the material. The main purpose of the present work has been to formulate a constitutive model that can accurately predict the unloading of a material. The new model is based on the classic elastic-plastic framework, and works together with any yield criterion and hardening evolution law. To determine the parameters of the new model, two different tests have been performed: unloading/reloading tests of uniaxially stretched specimens, and vibrometric tests of prestrained sheet strips. The performance of the model has been evaluated in simulations of the springback of simple U-bends and a drawbead example. Four different steel grades have been studied in the present investigation.

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Numerical Modeling of Macroscopic Behavior of Particulate Composite with Crosslinked Polymer Matrix

2011 ◽  
Vol 465 ◽  
pp. 129-132
Author(s):  
Luboš Náhlík ◽  
Bohuslav Máša ◽  
Pavel Hutař
Keyword(s):  
Young’S Modulus ◽  
Polymer Matrix ◽  
Young's Modulus ◽  
Numerical Models ◽  
Strain Curve ◽  
Particulate Composite ◽  
Material Behavior ◽  
Particulate Composites ◽  
Stress Strain ◽  
Crosslinked Polymer

Particulate composites with crosslinked polymer matrix and solid fillers are one of important classes of materials such as construction materials, high-performance engineering materials, sealants, protective organic coatings, dental materials, or solid explosives. The main focus of a present paper is an estimation of the macroscopic Young’s modulus and stress-strain behavior of a particulate composite with polymer matrix. The particulate composite with a crosslinked polymer matrix in a rubbery state filled by an alumina-based mineral filler is investigated by means of the finite element method. A hyperelastic material behavior of the matrix was modeled by the Mooney-Rivlin material model. Numerical models on the base of unit cell were developed. The numerical results obtained were compared with experimental stress-strain curve and value of initial Young’s modulus. The paper can contribute to a better understanding of the behavior and failure of particulate composites with a crosslinked polymer matrix.

Sign in / Sign up

Export Citation Format

Share Document