scholarly journals In‐situ force measurement during nano‐indentation combined with Laue microdiffraction

Nano Select ◽  
2020 ◽  
Author(s):  
Florian Lauraux ◽  
Sarah Yehya ◽  
Stéphane Labat ◽  
Jean‐Sébastien Micha ◽  
Odile Robach ◽  
...  
Keyword(s):  
Force Measurement ◽  
Nano Indentation ◽  
In Situ Force ◽  
Laue Microdiffraction

A Plexiglas Research Pump With Calibrated Magnetic Bearings/Load Cells for Radial and Axial Hydraulic Force Measurement

1999 ◽  
Vol 121 (1) ◽  
pp. 126-132 ◽  
Author(s):  
D. O. Baun ◽  
R. D. Flack
Keyword(s):  
Force Measurement ◽  
Radial Force ◽  
Design Flow ◽  
Magnetic Bearings ◽  
Force Measurements ◽  
Axial Thrust ◽  
In Situ Force ◽  
Load Cells ◽  
Radial Thrust

A research pump intended for both flow visualization studies and direct measurement of hydrodynamic radial and axial forces has been developed. The impeller and the volute casing are constructed from Plexiglas which facilitates optical access for laser velocimetry measurements of the flow field both inside the impeller and in the volute casing. The pump housing is designed for flexibility allowing for each interchange of impellers and volute configurations. The pump rotor is supported by three radial magnetic bearings and one double acting magnetic thrust bearing. The magnetic bearings have been calibrated to characterize the force versus coil current and air gap relationship for each bearing type. Linear calibration functions valid for rotor eccentricities of up to 2/3 of the nominal bearing clearances and force level of ±58 N (13 lbf) and ±267 N (60 lbf) for the radial and axial bearings, respectively, were found. A detailed uncertainty analysis of the force calibration functions was conducted such that meaningful uncertainty bounds can be applied to in situ force measurements. Hysteresis and eddy current effects were quantified for each bearing such that their effect on the in situ force measurements could be assessed. By directly measuring the bearing reaction forces it is possible to determine the radial and axial hydraulic loads acting on the pump impeller. To demonstrate the capability of the magnetic bearings as active load cells representative hydraulic force measurements for a centered 4 vane 16 degree log spiral radial flow impeller operating in a single tongue spiral volute casing were made. At shut-off a nondimensional radial thrust of 0.084 was measured. A minimum nondimensional radial thrust of about 0.007 was observed at the nominal design flow. The nondimensional radial thrust increased to about 0.019 at 120 percent of design flow. The nondimensional axial thrust had a maximum at shut-off of 0.265 and decreased steadily to approximately 0.185 at 120 percent of design flow. Two regions of increasing axial thrust, in the flow range 75 to 100 percent of design flow, were observed. The measurements are compared to radial and axial force predictions using classical force models. The direct radial force measurements are compared to a representative set of radial force measurements from the literature. In addition, the directly measured radial force at design flow is compared to a single representative radial force measurement (obtained from the literature) calculated from the combination of static pressure and net momentum flux distribution at the impeller exit.

scholarly journals In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

2016 ◽  
Vol 108 (21) ◽  
pp. 211902 ◽  
Author(s):  
Xian Chen ◽  
Nobumichi Tamura ◽  
Alastair MacDowell ◽  
Richard D. James
Keyword(s):  
Phase Transformation ◽  
In Situ Characterization ◽  
X Ray ◽  
Reversible Phase ◽  
Laue Microdiffraction

scholarly journals A device for testing the dynamic performance of in situ force plates

2017 ◽  
Vol 231 (9) ◽  
pp. 923-927
Author(s):  
Rebecca H East ◽  
Jonathan J Noble ◽  
Richard A Arscott ◽  
Adam P Shortland
Keyword(s):  
Dynamic Performance ◽  
In Situ Force

Nanoclay-reinforced Polyacrylamide Composite: Synthesis, Structural and Mechanical Characterization

2009 ◽  
Vol 1239 ◽  
Author(s):  
Yong Sun ◽  
Zaiwang Huang ◽  
Xiaodong Li
Keyword(s):  
Thin Films ◽  
Deformation Behavior ◽  
Mechanical Characterization ◽  
Interfacial Strength ◽  
Localized Deformation ◽  
Nano Indentation ◽  
Atomic Force ◽  
Nanocomposite Thin Films ◽  
Synthesized Materials

AbstractA facile electrophoretic deposition method was successfully applied to achieve novel nanoclay-reinforced polyacrylamide nanocomposite thin films. A special curled architecture of the re-aggregated nanoclay-platelets was identified, providing a possible source for realizing the interlocking mechanism in the nanocomposites. The curled architecture could be the result from strain releasing when the thin films were peeled off from the substrates. Through micro-/nano-indentation and in situ observation of the deformation during tensile test with an atomic force microscope (AFM), the localized deformation mechanism of the synthesized materials was investigated in further details. The results implied that a localized crack diversion mechanism worked in the synthesized nanocomposite thin films, which resembled its nature counterpart-nacre. The deformation behavior and fracture mechanism were discussed with reference to lamellar structure, interfacial strength between the nanoclays and the polyacrylamide matrix, and nanoclay agglomeration.

Bohrwiderstandsmessungen, eine neue und standardisierbare Methode zur Bestimmung der Kohäsion von Naturstein: Entwicklung eines Prototypes und dessen Erprobung / Drilling force measurement system, a new standardisa i methodology to determine the stone cohesion: Prototype design and validation

2000 ◽  
Vol 6 (2) ◽  
pp. 115-132 ◽  
Author(s):  
P. Tiano ◽  
C. Filareto ◽  
S. Ponticelli ◽  
M. Ferrari ◽  
E. Valentini
Keyword(s):  
Force Measurement ◽  
Direct Determination ◽  
Drilling Force ◽  
System A ◽  
Stone Materials ◽  
Force Measurement System ◽  
Drilling Resistance ◽  
Non Destructive

Abstract In the field of conservation of monumental buildings actually a standard methodology is lacking, with which it is possible to determine with the same sensitivity and reliability the "stone hardness" both at the superficial surface and at larger depths (few centimetres), both in laboratory and in situ. The use of the drilling resistance to determine the stone hardness is a very recent application and few working outdoor devices exist. The objective of this work is to validate a new and improved system to assess the drilling resistance of stones. The DFMS is portable and a quasi non-destructive device for direct determination of the "cohesion" of stone materials through the determination of their drilling resistance. The best operational features of the prototype have been established together with the assessment of the sensitivity and reliability of the system.

Development of Surface Skin Friction Measurement Technique Based on Compliant Coatings

2007 ◽  
Author(s):  
Nobuyoshi Fujimatsu ◽  
Isao Misu
Keyword(s):  
Skin Friction ◽  
Friction Force ◽  
Force Measurement ◽  
A Priori ◽  
Ccd Camera ◽  
Flow Speed ◽  
Polymeric Film ◽  
Wide Range ◽  
Unsteady Characteristics

New method and means are proposed to measure the skin friction force on an aerodynamic surface based on elastic deformations of silicon rubber and gel coatings. One of characteristics is soft and easy to deform. Object is coated by elastic polymeric film with known shear modulus. Two images between wind-on and wind-off are taken using the CCD camera. The displacement of coating is calculated from the correlation of two images. There are two ways to calibrate the skin friction force to the displacement of coatings. These methods are tested and compared to quantitative skin friction force measurement. One is based on measuring the characteristics of the polymeric film using visco-elastic measurement system. This way is called as a priori calibration. The other way is accomplished from the relation between the skin friction force measured by the PHF embedded on the object and the displacement around there and is known as In-situ method. Characteristics of the coatings such as the displacement and the time response can be easily controlled by the compounding ratio of hardener. We conduct the theoretical analysis for the elastic polymer film and propose the material properties of the coatings required to measure the surface skin friction in the wide range of flow speed. The skin friction over the plate is measured using this technique in various Reynolds number. The traditional measurement using the hot wire anemometry is conducted to validate this technique. The time averaged measurements of this technique are in good agreement with the traditional results. However, the unsteady characteristics of surface skin friction are not captured by the lack of time resolution of the CCD camera.

scholarly journals Versatile and High-throughput Force Measurement Platform for Dorsal Cell Mechanics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Seungman Park ◽  
Yoon Ki Joo ◽  
Yun Chen
Keyword(s):  
High Throughput ◽  
Cell Mechanics ◽  
Force Measurement ◽  
Time Lapse ◽  
Dorsal Side ◽  
Single Particle Tracking ◽  
Single Experiment ◽  
Molecular Binding ◽  
Force Magnitude

Abstract We present a high-throughput microfluidics technique facilitating in situ measurements of cell mechanics parameters at the dorsal side of the cell, including molecular binding strengths, local traction forces, and viscoelastic properties. By adjusting the flow rate, the force magnitude exerted on the cell can be modulated ranging from ~14 pN to 2 nN to perturb various force-dependent processees in cells. Time-lapse images were acquired to record events due to such perturbation. The values of various mechanical parameters are subsequently obtained by single particle tracking. Up to 50 events can be measured simultaneously in a single experiment. Integrating the microfluidic techniques with the analytic framework established in computational fluid dynamics, our method is physiologically relevant, reliable, economic and efficient.

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