Accurate Determination of the Elastic properties of Near Surface Regions and Thin Films Using Nanoindentation and Acoustic Microscopy

2001 ◽  
Vol 695 ◽  
Author(s):  
Matthew Bamber ◽  
Adrian Mann ◽  
Brian Derby
Keyword(s):  
Thin Films ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Accurate Determination ◽  
Acoustic Microscopy ◽  
Poisson's Ratio ◽  
Near Surface

ABSTRACTNanoindentation has been successfully used as a mechanical properties microprobe to characterise the elastic properties of materials. However, in an isotropic material it is not possible to measure the two independent elastic constants by nanoindentation. Normally, a value of Young's modulus is determined using an assumed value for Poisson's ratio. It is also possible to use the acoustic microscope in its z-contrast mode to measure the elastic constants of a surface. This too produces a composite measurement of the elastic properties, which can be represented in terms of Young's modulus and Poisson's ratio. By using both techniques on the same sample area, it is possible to make two independent measurements of the elastic properties and thus determine both Young's modulus and Poisson's ratio. This method has been used on well-characterised bulk materials, e.g. silica glass, to demonstrate that it produces consistent results. It has also been uused to characterise thin films of TiN/NbN multilayers. These results show that, although for thin films there is a need to improve the analysis of the mechanics, the combination of nanoindentation and acoustic microscopy shows promise.

scholarly journals On the identification of the eggshell elastic properties under quasistatic compression

2004 ◽  
Vol 52 (5) ◽  
pp. 73-82 ◽  
Author(s):  
Jana Simeonovová ◽  
Jaroslav Buchar
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Rotational Shell ◽  
Mutual Comparison ◽  
Quasistatic Loading

The problem of the identification of the elastic properties of eggshell, i.e. the evaluation of the Young's modulus and Poisson's ratio is solved. The eggshell is considered as a rotational shell. The experiments on the egg compression under quasistatic loading have been conducted. During these experiments a strain on the eggshell surface has been recorded. By the mutual comparison between experimental and theoretical values of strains the influence of the elastic constants has been demonstrated.

scholarly journals PPV Criterion of a Rock Slope Imbedded with a Fault subjected to Blasting P-Waves

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Shiwei Lu ◽  
Chuanbo Zhou ◽  
Zhen Zhang ◽  
Ling Ji ◽  
Nan Jiang
Keyword(s):  
Slope Stability ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Rock Slope ◽  
Young's Modulus ◽  
Intact Rock ◽  
P Wave ◽  
Poisson's Ratio ◽  
Rock Slopes ◽  
Near Surface

The open-pit mining slopes continue to become higher and steeper with the continuous exploitation of near-surface mineral resources. The blasting excavation exerts a significance influence on the slope stability. In fact, intact rock slopes do not exist and slope stability is controlled by the geological defects. In this paper, the stability of a rock slope imbedded with a fault is considered. The P-wave component of blasting seismic waves is focused on and the fault is simplified as a semi-infinite crack. In background of Daye iron mine, the peak particle velocity (PPV) threshold is determined based on the linear elastic fracture dynamics. The influence of frequency, Young's modulus, and Poisson's ratio is studied to modify the PPV threshold. Results show that (1) the PPV threshold decreases with the increasing Young's modulus and Poisson's ratio, but increases with the increasing frequency; (2) the initiation angle is immune to Young's modulus and the frequency, and only depends on the Poisson's ratio; (3) the PPV criterion is finally determined as 1.47 cm/s when the frequency f ≤ 10 Hz, 1.47 cm/s–3.30 cm/s when 10 Hz < f ≤ 50 Hz and 3.37 cm/s–6.59 cm/s when f > 50 Hz, which are far less than that of intact rock slopes; (4) The north slope is quite safe if the proposed PPV threshold is not violated due to the variation range of the initiation angle θ0.

scholarly journals Thermally Tunable Dynamic and Static Elastic Properties of Hydrogel Due to Volumetric Phase Transition

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1462 ◽  
Author(s):  
Yuqi Jin ◽  
Teng Yang ◽  
Shuai Ju ◽  
Haifeng Zhang ◽  
Tae-Youl Choi ◽  
...  
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Alginate Hydrogel

The temperature dependence of the mechanical properties of polyvinyl alcohol-based poly n-isopropyl acrylamide (PVA-PNIPAm) hydrogel was studied from the static and dynamic bulk modulus of the material. The effect of the temperature-induced volumetric phase transition on Young’s Modulus, Poisson’s ratio, and the density of PVA-PNIPAm was experimentally measured and compared with a non-thermo-responsive Alginate hydrogel as a reference. An increase in the temperature from 27.5 to 32 °C results in the conventional temperature-dependent de-swelling of the PVA-PNIPAm hydrogel volume of up to 70% at the lower critical solution temperature (LCST). However, with the increase in temperature, the PVA-PNIPAm hydrogel showed a drastic increase in Young’s Modulus and density of PVA-PNIPAm and a corresponding decrease in the Poisson’s ratio and the static bulk modulus around the LCST temperature. The dynamic bulk modulus of the PVA-PNIPAm hydrogel is highly frequency-dependent before the LCST and highly temperature-sensitive after the LCST. The dynamic elastic properties of the thermo-responsive PVA-PNIPAm hydrogel were compared and observed to be significantly different from the thermally insensitive Alginate hydrogel.

Prediction of Elastic Constants of Carbon Fabric/Polyurethane Composites

2016 ◽  
Vol 258 ◽  
pp. 233-236 ◽  
Author(s):  
Shun Fa Hwang ◽  
Hsuan Ting Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Element Model ◽  
Curing Temperature ◽  
Poisson's Ratio ◽  
Fiber Fabric

The purpose of this work is to study a new composite material consisting of polyurethane (PU) resin and carbon fiber fabric. This PU resin is superior in impact, viscosity, low curing temperature, and short curing time. If this resin is combined with fiber fabric by vacuum assisted resin transfer method, the fabrication time will be short. Since it is a braided composite, it’s important to have a model to predict the elastic constants for different braid angels. To predict the elastic constants including Young’s modulus, shear modulus, and Poisson’s ratio, a finite element model is established. In this model a braided layer is treated as two uni-directional layers. Then, the elastic constants of this composite with different braid angels are estimated. After that, the composites with different braid angels are fabricated and tested to obtain the elastic constants, and the comparison with the finite element results is made. The results indicate that the agreement is very good for the Young’s modulus. For the Poisson’s ratio, the difference between the prediction and the measurement is reasonable. From the comparison, it can be concluded that the finite element model is good. Then, this model is used to predict all in-plane elastic constants for arbitrary braid angles.

Measurement of Mechanical Properties for Thin Film Using Visual Image Tracing Method

2007 ◽  
Vol 124-126 ◽  
pp. 1701-1704 ◽  
Author(s):  
Sang Joo Lee ◽  
Seung Woo Han ◽  
Jae Hyun Kim ◽  
Hak Joo Lee
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Measurement System ◽  
Strain Measurement ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Visual Image ◽  
Poisson's Ratio

It is quite difficult to accurately measure the mechanical properties of thin films. Currently, there are several methods (or application) available for measuring mechanical properties of thin films. Their properties, however, have been determined by indirect methods such as cantilever beam test and diaphragm bulge test. This paper reports the efforts to develop a direct strain measurement system for micro/nano scale thin film materials. The proposed solution is the Visual Image Tracing (VIT) strain measurement system coupled with a micro tensile testing unit, which consists of a piezoelectric actuator, load cell, microscope and CCD cameras. The advantage of this system is the ability to monitor the real time images of specimen during the test in order to determine its Young’s modulus and Poisson’s ratio at the same time. Stress-strain curve, Young’s modulus, yield strength and Poisson’s ratio of copper thin film measured using VIT system are presented.

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