Complete contact trajectory visualization based on triboelectrification and droplet luminescence

2021 ◽  
Vol 24 ◽  
pp. 101081
Author(s):  
Changhui Song ◽  
Shicai Zhu ◽  
Liran Ma ◽  
Yu Tian ◽  
Jianbin Luo
Keyword(s):  
Complete Contact

Development of a complete contact fretting test device

2012 ◽  
Vol 227 (6) ◽  
pp. 570-578 ◽  
Author(s):  
Janne Juoksukangas ◽  
Arto Lehtovaara ◽  
Antti Mäntylä
Keyword(s):  
Test Device ◽  
Complete Contact

Multiple Region Contact Solutions for a Flat Indenter on a Layered Elastic Half Space: Plane-Strain Case

1989 ◽  
Vol 56 (2) ◽  
pp. 251-262 ◽  
Author(s):  
T. W. Shield ◽  
D. B. Bogy
Keyword(s):  
Plane Strain ◽  
Half Space ◽  
Contact Region ◽  
Integral Transforms ◽  
Elastic Half Space ◽  
Geometrical Parameters ◽  
Restricted Range ◽  
Complete Contact ◽  
The One ◽  
Layered Half Space

The plane-strain problem of a smooth, flat rigid indenter contacting a layered elastic half space is examined. It is mathematically formulated using integral transforms to derive a singular integral equation for the contact pressure, which is solved by expansion in orthogonal polynomials. The solution predicts complete contact between the indenter and the surface of the layered half space only for a restricted range of the material and geometrical parameters. Outside of this range, solutions exist with two or three contact regions. The parameter space divisions between the one, two, or three contact region solutions depend on the material and geometrical parameters and they are found for both the one and two layer cases. As the modulus of the substrate decreases to zero, the two contact region solution predicts the expected result that contact occurs only at the corners of the indenter. The three contact region solution provides an explanation for the nonuniform approach to the half space solution as the layer thickness vanishes.

Morphological and adhesive changes to cultured chick kidney cells following parasitization with Eimeria tenella (Protozoa: Coccidia)

Parasitology ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Catriona Urquhart
Keyword(s):  
Separation Distance ◽  
Eimeria Tenella ◽  
Con A ◽  
Interference Microscope ◽  
Cell Substrate ◽  
Gradual Loss ◽  
Cytoplasmic Bridges ◽  
Loss Of Contact ◽  
Complete Contact ◽  
Chick Kidney

SUMMARYCultured adult chick kidney (CK) cells inoculated with sporozoites of Eimeria tenella showed progressive alterations in their morphological and adhesive characteristics. Scanning electron microscopy (SEM) showed that during a 3-day period following the inoculation of parasites there was a gradual loss of contact between the cells. Initially, the cells remained connected by long cytoplasmic bridges but with the breakdown of these, the cells began to round up, losing complete contact with each other and remaining attached to the substratum by means of retraction fibres. By 3 days many cells had completely detached. The factors inducing these alterations were transmissable via the medium as the alterations were mimicked by non-parasitized cells in co-culture with parasitized cells. Studies with the reflection interference microscope (RIM) showed that the changes were accompanied by an increase in the cell-substrate separation distance and the loss of focal contacts. These changes were not effected by substances transmissable via the medium. Parasitized cells showed enhanced agglutination with Concanavalin A (Con A) which could be eliminated by pre-fixation. The possibility that changes to the host cell indicate a rearrangement of cytoskeletal apparatus is discussed.

Dynamic response of a pre-stressed bi-layered plate-strip subjected to an arbitrary inclined time-harmonic force

2017 ◽  
Vol 26 (3) ◽  
pp. 255-262
Author(s):  
AHMET DASDEMIR ◽  
Keyword(s):  
Dynamic Response ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Layered Plate ◽  
Field Problem ◽  
Time Harmonic ◽  
Governing System ◽  
Plate Strip ◽  
Linearized Theory ◽  
Complete Contact

Within the scope of the piecewise homogeneous body model with utilizing of the three dimensional linearized theory of elastic waves in initially stressed bodies the dynamical stress field problem in a bi-layered plate-strip with initial stress under the action of an arbitrary inclined timeharmonic force resting on a rigid foundation is investigated. The concrete materials such as a pair of Aluminum and Steel are selected. It is assumed that there exists a complete contact interaction between the layers. The mathematical modeling of the problem under consideration is carved out, and the governing system of the partial differential equations of motion is approximately solved by employing Finite Element Method. The numerical results related to the influence of certain parameters on the dynamic response of the plate-strip are presented.

Shakedown in Frictional Contact Problems

2007 ◽  
Author(s):  
J. R. Barber ◽  
A. Klarbring ◽  
M. Ciavarella
Keyword(s):  
Frictional Contact ◽  
Elastic System ◽  
Contact Problems ◽  
Sufficient Condition ◽  
Normal Contact ◽  
Linear Elastic ◽  
Periodic Loading ◽  
Continuum Formulation ◽  
Complete Contact ◽  
The Continuum

If a linear elastic system with frictional interfaces is subjected to periodic loading, any slip which occurs generally reduces the tendency to slip during subsequent cycles and in some circumstances the system ‘shakes down’ to a state without slip. It has often been conjectured that a frictional Melan’s theorem should apply to this problem — i.e. that the existence of a state of residual stress sufficient to prevent further slip is a sufficient condition for the system to shake down. Here we discuss recent proofs that this is indeed the case for ‘complete’ contact problems if there is no coupling between relative tangential displacements at the interface and the corresponding normal contact tractions. By contrast, when coupling is present, the theorem applies only for a few special two-dimensional discrete cases. Counter-examples can be generated for all other cases. These results apply both in the discrete and the continuum formulation.

Crack tip stress intensity factors for a crack emanating from a semi-infinite notch with application to the avoidance of fatigue in complete contacts

2008 ◽  
Vol 223 (4) ◽  
pp. 789-794 ◽  
Author(s):  
A G Philipps ◽  
S Karuppanan ◽  
N Banerjee ◽  
D A Hills
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Crack Tip ◽  
Crack Development ◽  
Short Crack ◽  
Length Scale ◽  
Intensity Factors ◽  
Reference Length ◽  
Complete Contact ◽  
Crack Tip Stress

Crack tip stress intensity factors are found for the problem of a short crack adjacent to the apex of a notch, and lying perpendicular to one of the notch faces. Loading is represented by the two Williams eigensolutions, the ratio between which provides a reference length scale and permits a comprehensive display of the solution. The results are applied to the problem of a crack starting from the edge of a notionally adhered complete contact, and conditions for the avoidance of crack development are found.

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