Presenting in-situ AFM investigations for the evolution of micro-surface topography and elastic modulus of rock under variable loads

2021 ◽  
pp. 108107
Author(s):  
Xianghui Tian ◽  
Dazhao Song ◽  
Xueqiu He ◽  
Majid Khan ◽  
Zhenlei Li ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Surface Topography

scholarly journals Biomimetic Transparent Eye Protection Inspired by the Carapace of an Ostracod (Crustacea)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 663
Author(s):  
Andrew R. Parker ◽  
Barbara P. Palka ◽  
Julie Albon ◽  
Keith M. Meek ◽  
Simon Holden ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Thin Film Deposition ◽  
Dielectric Materials ◽  
Scratch Resistance ◽  
Film Deposition ◽  
Original Form ◽  
Biomimetic Material ◽  
Eye Protection ◽  
Protection Coating

In this study we mimic the unique, transparent protective carapace (shell) of myodocopid ostracods, through which their compound eyes see, to demonstrate that the carapace ultrastructure also provides functions of strength and protection for a relatively thin structure. The bulk ultrastructure of the transparent window in the carapace of the relatively large, pelagic cypridinid (Myodocopida) Macrocypridina castanea was mimicked using the thin film deposition of dielectric materials to create a transparent, 15 bi-layer material. This biomimetic material was subjected to the natural forces withstood by the ostracod carapace in situ, including scratching by captured prey and strikes by water-borne particles. The biomimetic material was then tested in terms of its extrinsic (hardness value) and intrinsic (elastic modulus) response to indentation along with its scratch resistance. The performance of the biomimetic material was compared with that of a commonly used, anti-scratch resistant lens and polycarbonate that is typically used in the field of transparent armoury. The biomimetic material showed the best scratch resistant performance, and significantly greater hardness and elastic modulus values. The ability of biomimetic material to revert back to its original form (post loading), along with its scratch resistant qualities, offers potential for biomimetic eye protection coating that could enhance material currently in use.

INVESTIGATION OF BIAXIAL ELASTIC MODULUS AND CTE OF BaTiO3 FILMS

2009 ◽  
Vol 23 (24) ◽  
pp. 4933-4941
Author(s):  
GUI-FANG HUANG ◽  
WEI-QING HUANG ◽  
LING-LING WANG ◽  
ZHONG XIE ◽  
BING-SUO ZOU ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Thermal Cycle ◽  
Laser Scanning ◽  
Stress Measurement ◽  
Coefficient Of Thermal Expansion ◽  
Bulk Material ◽  
Good Reliability ◽  
Scanning Method ◽  
As Stress

To develop high-quality film device with good reliability, it is often essential to be able to evaluate the parameters such as stress, the biaxial elastic modulus, and coefficient of thermal expansion (CTE) of film. Based on the stress measurement in situ during the thermal cycle by laser scanning method, two techniques were used to measure the biaxial elastic modulus and CTE of BaTiO 3 films deposited on substrate. The value of the biaxial elastic modulus and CTE for BaTiO 3 films determined from two methods is close, in which the biaxial elastic modulus of BaTiO 3 films is higher than that of corresponding bulk while the CTE of BaTiO 3 films is a little smaller than that of bulk material.

Test Methods for Mechanical Properties of Structural Adhesives

2010 ◽  
Vol 97-101 ◽  
pp. 814-817 ◽  
Author(s):  
Jun Deng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Elastic Modulus ◽  
Butt Joint ◽  
Test Methods ◽  
Joint Specimen ◽  
Lap Shear ◽  
Better Than

One of the greatest drawbacks to predicting the behaviour of bonded joints has been the lack of reliable data on the mechanical properties of adhesives. In this study, methods for determining mechanical properties of structural adhesive were discussed. The Young’s modulus, Poisson’s ratio and tensile strength of the adhesive were tested by dogbone specimens (bulk form) and butt joint specimens (in situ form). The shear modulus and shear strength were test by V-notched specimens (bulk form) and thick adherend lap-shear (TALS) joint specimens (in situ form). The test results show that the elastic modulus provided by the manufacturer is too low, the dogbone specimen is better than the butt joint specimen to test the tensile strength and elastic modulus and the TALS joint specimen is better than the V-notched specimen to test the shear strength.

Measurement of Cement in Situ Stresses and Mechanical Properties Without Cooling or Depressurization

2021 ◽  
Author(s):  
Meng Meng ◽  
Luke Frash ◽  
James Carey ◽  
Wenfeng Li ◽  
Nathan Welch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Elastic Modulus ◽  
Poisson’S Ratio ◽  
Axial Stress ◽  
Triaxial Compression ◽  
In Situ Measurement ◽  
Poisson's Ratio ◽  
Ambient Conditions

Abstract Accurate characterization of oilwell cement mechanical properties is a prerequisite for maintaining long-term wellbore integrity. The drawback of the most widely used technique is unable to measure the mechanical property under in situ curing environment. We developed a high pressure and high temperature vessel that can hydrate cement under downhole conditions and directly measure its elastic modulus and Poisson's ratio at any interested time point without cooling or depressurization. The equipment has been validated by using water and a reasonable bulk modulus of 2.37 GPa was captured. Neat Class G cement was hydrated in this equipment for seven days under axial stress of 40 MPa, and an in situ measurement in the elastic range shows elastic modulus of 37.3 GPa and Poisson's ratio of 0.15. After that, the specimen was taken out from the vessel, and setted up in the triaxial compression platform. Under a similar confining pressure condition, elastic modulus was 23.6 GPa and Possion's ratio was 0.26. We also measured the properties of cement with the same batch of the slurry but cured under ambient conditions. The elastic modulus was 1.63 GPa, and Poisson's ratio was 0.085. Therefore, we found that the curing condition is significant to cement mechanical property, and the traditional cooling or depressurization method could provide mechanical properties that were quite different (50% difference) from the in situ measurement.

scholarly journals In situ elastic modulus measurements of ultrathin protein-rich organic layers in biosilica: towards deeper understanding of superior resistance to fracture of biocomposites

RSC Advances ◽  
2013 ◽  
Vol 3 (17) ◽  
pp. 5798 ◽  
Author(s):  
Igor Zlotnikov ◽  
Doron Shilo ◽  
Yannicke Dauphin ◽  
Horst Blumtritt ◽  
Peter Werner ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Organic Layers ◽  
Protein Rich

Mechanical and Dimensional Adaptation of Rat Aorta to Hypertension

1994 ◽  
Vol 116 (3) ◽  
pp. 278-283 ◽  
Author(s):  
T. Matsumoto ◽  
K. Hayashi
Keyword(s):  
Blood Pressure ◽  
Elastic Modulus ◽  
Wall Stress ◽  
Dimensional Change ◽  
Biological Tissues ◽  
Rat Aorta ◽  
Mechanical Adaptation ◽  
Male Wistar Rats ◽  
Load Effects

To investigate mechanisms of the mechanical adaptation of soft biological tissues to load, effects of hypertension on the mechanical properties and wall dimensions of thoracic aortas were studied in rats. Goldblatt hypertension was induced in male Wistar rats aged 8 to 9 weeks by constricting their left renal arteries. Two, 4, 8, or 16 weeks after the operation, thoracic aortas were excised and used to determine static pressure-diameter relations and wall dimensions. Wall thickness correlated significantly with the systolic blood pressure before sacrifice, Psys, at each period. The aortic hoop stress became almost constant at all Psys 2 weeks after the operation. On the other hand, the stress calculated for 100 and 200 mmHg correlated negatively with Psys. The incremental elastic modulus of the wall at Psys had a significant correlation with Psys having a positive slope at each period, although the correlation disappeared at 16 weeks after the operation. These results imply that: 1) thickness of the aortic wall increases very rapidly in response to hypertension; 2) wall stress developed by the in-situ blood pressure is kept constant at a normal level irrespective of hypertension; 3) elastic modulus of the wall of the hypertensive rats at the in-situ blood pressure becomes equal to the normal value after relatively long period of time; 4) in response to the alteration of the applied force, dimensional change appears much earlier than the change in the elastic properties.

scholarly journals Assessment of the Shear Strength of Pile-to-Soil Interfaces Based on Pile Surface Topography Using Laser Scanning

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1012 ◽  
Author(s):  
Zbigniew Muszyński ◽  
Marek Wyjadłowski
Keyword(s):  
Shear Strength ◽  
Surface Topography ◽  
Friction Factor ◽  
Laser Scanning ◽  
Least Squares Method ◽  
Soil Layer ◽  
Side Surface ◽  
Sample Height ◽  
Functional Volume

This article presents in situ research on the side surface of continuous flight auger (CFA) foundation piles using a three-dimensional (3D) laser scanner (Leica ScanStation C10) in order to evaluate the morphology assessment of pile concrete surfaces in various geotechnical layers. Terrestrial laser scanning describes the 3D geometry of the construction with high spatial resolution and accuracy. A total of six areas were selected from the acquired point cloud for which a two-step approach for removing the form was applied. In the first step, the reference surface was fitted using the least squares method, and then, cylindrical projection of the surface was performed. In the second step, an operator of removal of the multi-plane form was applied. For each sample, height parameters (Sq, Ssk, Sku, Sp, Sv, Sz, Sa) and functional volume parameters (Vmp, Vmc, Vvc, Vvv) according to the standard ISO 25178-2:2012 were determined. Significant differences in the values of surface height and functional volume parameters were observed for each geotechnical layer where piles were formed. Because the piles remain embedded in the ground, in situ tests of the side surface of piles are rarely performed and taken into account in the assessment of pile bearing capacity. The study of surface topography is a crucial stage in the assessment of the shear strength at the interface between a concrete pile and the soil layer. The obtained concrete morphology assessments are applicable during the determination of the skin friction factor in the analytical or numerical estimation of pile shaft resistance. The proposed procedure of morphology evaluation may improve the fidelity of the assumed friction factor between the concrete and soil and increase the reliability of direct shear experiments.

Electrical Determination of Elastic Modulus of Individual PZT Nanofibers by In Situ SEM

2011 ◽  
Author(s):  
Xi Chen ◽  
Yong Shi
Keyword(s):  
Elastic Modulus ◽  
Resonant Frequency ◽  
Lead Zirconate Titanate ◽  
Electrical Measurement ◽  
Lead Zirconate ◽  
Electrospinning Process ◽  
Frequency Spectra ◽  
Oscillating Electric Field ◽  
The Individual

We present an electrical measurement of elastic modulus of single electrospun lead zirconate titanate (PZT) nanofibers under harmonic vibration using in situ scanning electron microscopy (SEM) equipped with a nanomanipulator. The PZT nanofiber was fabricated using an electrospinning process and collected on a silicon substrate with 10 μm trenches. The individual PZT nanofibers were excited with an oscillating electric field applied by a network analyzer and the resonant frequency was observed through the SEM along with the transfer frequency spectra simultaneously. The elastic modulus was calculated as ∼70 GPa from this resonant frequency using Euler-Bernoulli equation.

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