The Line Contact Between Two Cylinders—Some Experiments and Theoretical Predictions

1988 ◽  
Vol 110 (2) ◽  
pp. 285-291 ◽  
Author(s):  
J. M. de Mul ◽  
H. van Engelenburg
Keyword(s):  
Half Space ◽  
Cross Section ◽  
Circular Cross Section ◽  
Infinite Cylinder ◽  
Space Model ◽  
Linear Elastic ◽  
Cylinder Model ◽  
Theoretical Predictions ◽  
Frictional Effects ◽  
Good Agreement

Experiments are presented in which various combinations of two (almost) straight cylinders with circular cross-section are pressed together while their axes remain basically parallel. Results are compared with theoretical predictions from a half space model; from this half space model extended with adjustments for the finite dimensions of the cylinders in contact; and from an infinite cylinder model from literature. Frictional effects are not considered and the material is assumed to be linear-elastic. Agreement in the approach of the center lines of the cylinders under load is found to exist more or less between the experimental results and the theoretical predictions by the models. The behaviour of the models is discussed, and reasonable to good agreement is demonstrated for the extended half space model using an integral depth adjustment of 3/4 of the diameter of each cylinder in contact. A possible way to further improve this model is indicated.

scholarly journals Asymptotic Behavior of Stable Structures Made of Beams

2021 ◽  
Author(s):  
Georges Griso ◽  
Larysa Khilkova ◽  
Julia Orlik ◽  
Olena Sivak
Keyword(s):  
Asymptotic Behavior ◽  
Cross Section ◽  
Cross Sections ◽  
Linear Elasticity ◽  
Circular Cross Section ◽  
Linear Elasticity Theory ◽  
Linear Elastic ◽  
The Cross ◽  
Small Rotation ◽  
Stable Structures

AbstractIn this paper, we study the asymptotic behavior of an $\varepsilon $ ε -periodic 3D stable structure made of beams of circular cross-section of radius $r$ r when the periodicity parameter $\varepsilon $ ε and the ratio ${r/\varepsilon }$ r / ε simultaneously tend to 0. The analysis is performed within the frame of linear elasticity theory and it is based on the known decomposition of the beam displacements into a beam centerline displacement, a small rotation of the cross-sections and a warping (the deformation of the cross-sections). This decomposition allows to obtain Korn type inequalities. We introduce two unfolding operators, one for the homogenization of the set of beam centerlines and another for the dimension reduction of the beams. The limit homogenized problem is still a linear elastic, second order PDE.

Rise in optimized capillary channels

2013 ◽  
Vol 731 ◽  
pp. 142-161 ◽  
Author(s):  
B. Figliuzzi ◽  
C. R. Buie
Keyword(s):  
Cross Section ◽  
Silicone Oil ◽  
Capillary Rise ◽  
Circular Cross Section ◽  
Heat Pipes ◽  
Design And Optimization ◽  
The Subject ◽  
Micro Heat Pipes ◽  
Good Agreement ◽  
Optimal Radius

AbstractMany technological applications rely on the phenomenon of wicking flow induced by capillarity. However, despite a continuing interest in the subject, the influence of the capillary geometry on the wicking dynamics remains underexploited. In numerous applications, the ability to promote wicking in a capillary is a key issue. In this article, a model describing the capillary rise of a liquid in a capillary of varying circular cross-section is presented. The wicking dynamics is described by an ordinary differential equation with a term dependent upon the shape of the capillary channel. Using optimal control theory, we were able to design optimized capillaries which promote faster wicking than uniform cylinders. Numerical simulations show that the height of the rising liquid was up to 50 % greater with the optimized shapes than with a uniform cylinder of optimal radius. Experiments on specially designed capillaries with silicone oil show a good agreement with the theory. The methods presented can be useful in the design and optimization of systems employing capillary-driven transport including micro-heat pipes or oil extracting devices.

scholarly journals Efficiency of Hysteresis Rods in Small Spacecraft Attitude Stabilization

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Assal Farrahi ◽  
Ángel Sanz-Andrés
Keyword(s):  
Thin Film ◽  
Cross Section ◽  
Circular Cross Section ◽  
Semiempirical Method ◽  
Spacecraft Attitude ◽  
Flight Data ◽  
Small Satellites ◽  
Attitude Stabilization ◽  
Section Shape ◽  
Good Agreement

A semiempirical method for predicting the damping efficiency of hysteresis rods on-board small satellites is presented. It is based on the evaluation of dissipating energy variation of different ferromagnetic materials for two different rod shapes: thin film and circular cross-section rods, as a function of their elongation. Based on this formulation, an optimum design considering the size of hysteresis rods, their cross section shape, and layout has been proposed. Finally, the formulation developed was applied to the case of four existing small satellites, whose corresponding in-flight data are published. A good agreement between the estimated rotational speed decay time and the in-flight data has been observed.

Spirally bound concrete columns

1985 ◽  
Vol 400 (1818) ◽  
pp. 127-144 ◽  
Keyword(s):  
Cross Section ◽  
Material Properties ◽  
Circular Cross Section ◽  
Plain Concrete ◽  
Concrete Columns ◽  
Stress Strain Relation ◽  
Mathematical Expressions ◽  
Iterative Procedures ◽  
Theoretical Results ◽  
Good Agreement

In this paper, mathematical expressions for the material properties of plain concrete are used in conjunction with the stress–strain relation of steel reinforcement to develop equations for both the strength and deformational behaviour of axially loaded concrete columns of circular cross section and with closely spaced spiral binding. Iterative procedures are used to solve these equations and the theoretical results are shown to be in good agreement with experimental results obtained by earlier investigators.

scholarly journals Total cross section of the reaction γd → π–pp in the threshold energy region

2020 ◽  
Vol 64 (2) ◽  
pp. 159-163 ◽  
Author(s):  
E. S. Kokoulina ◽  
M. I. Levchuk ◽  
M. N. Nevmerzhitsky ◽  
R. G. Shulyakovsky
Keyword(s):  
Plane Wave ◽  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Threshold Energy ◽  
Impulse Approximation ◽  
Final State ◽  
Plane Wave Impulse Approximation ◽  
Theoretical Predictions ◽  
Good Agreement

In the framework of the diagrammatic approach, the total cross section of near-threshold π– photoproduction on the deuteron is calculated. Contributions of the diagrams corresponding to the plane wave impulse approximation as well as to NN- and πN-interactions in the final state have been taken into account. We have compared the theoretical predictions with the results of the recent measurements performed at the MAX IV laboratory of the Lund University. There is good agreement with the data at photon energies from 147 to 155 MeV. However, at 158 and 160 MeV, the theoretical predictions significantly overestimate the measured cross sections.

Steady long slender droplets in two-dimensional straining motion

1979 ◽  
Vol 91 (3) ◽  
pp. 401-414 ◽  
Author(s):  
E. J. Hinch ◽  
A. Acrivos
Keyword(s):  
Cross Section ◽  
Experimental Results ◽  
Recent Analysis ◽  
Two Dimensional ◽  
Axisymmetric Case ◽  
Hyperbolic Flow ◽  
Theoretical Criterion ◽  
Theoretical Predictions ◽  
The Cross ◽  
Good Agreement

The recent analysis by Acrivos & Lo (1978) concerning the breakup of a long slender droplet in an axisymmetric straining motion is extended to the case of a two-dimensional hyperbolic flow. It is found that, although the cross-section of the droplet becomes significantly non-circular, the theoretical criterion for breakup is effectively the same as in the axisymmetric case. The theoretical predictions are in good agreement with the available experimental results.

Deformation Analysis of a Radial Tire Loaded on a Crossbar

1993 ◽  
Vol 21 (1) ◽  
pp. 40-63 ◽  
Author(s):  
T. Akasaka ◽  
S. Kagami ◽  
S. Yamazaki
Keyword(s):  
Large Deformation ◽  
Cross Section ◽  
Structural Factor ◽  
Deformation Analysis ◽  
Radial Tire ◽  
Ring Model ◽  
Theoretical Predictions ◽  
The Cross ◽  
Good Agreement

Abstract The spring characteristics of a radial tire loaded on a crossbar put on a roadway was analyzed with a spring bedded ring model. Nonlinear radial and tangential spring effects of the sidewall and large deformation of the tread were considered. The tread curvature in the cross section was found to be the most important structural factor for elucidating the enveloping properties of a radial tire in contact with a crossbar. Experimental verifications of the spring effect and the tread deformation of a radial tire were in good agreement with the theoretical predictions.

Effect of contributions from bending in evaluation of axial strain in rods with circular cross-section

1983 ◽  
Vol 18 (1) ◽  
pp. 77-79 ◽  
Author(s):  
L Lagerkvist ◽  
K-G Sundin ◽  
B Lundberg
Keyword(s):  
Cross Section ◽  
Axial Strain ◽  
Circular Cross Section ◽  
Strain Gauges ◽  
Elastic Rod ◽  
Simple Method ◽  
Strain Measurements ◽  
Absolute Value ◽  
Bending Strain ◽  
Good Agreement

Contributions from bending to the evaluated axial strain in an elastic rod are commonly suppressed by forming half the sum of measured surface strains at diametrically opposite positions. A simple method is presented which gives a useful estimation of the bending suppression (the ratio of the bending strain to the absolute value of the evaluated axial strain when a rod is subject to bending only) from (i) optically measured mis-positioning, and (ii) estimated differences between the gauge constants for the two strain gauges. Good agreement is obtained with results obtained from strain measurements on a rod loaded in bending.

An experimental study of gas exchange in laminar oscillatory flow

1983 ◽  
Vol 133 ◽  
pp. 245-254 ◽  
Author(s):  
C. H. Joshi ◽  
R. D. Kamm ◽  
J. M. Drazen ◽  
A. S. Slutsky
Keyword(s):  
Experimental Study ◽  
Cross Section ◽  
Oscillatory Flow ◽  
Circular Cross Section ◽  
Effective Diffusivity ◽  
Constant Infusion ◽  
Tracer Gas ◽  
Theoretical Predictions ◽  
Induced Flow ◽  
Buoyancy Induced Flow

Experiments were conducted to determine the effective diffusivity for axial transport through a tube of circular cross-section of a contaminant gas in oscillatory flow. Results were compared with the theoretical predictions of Watson (1983) and found to be in excellent agreement. The experiments differ from the theoretical situation in that the oscillations are superimposed upon a steady flow due to a constant infusion of tracer gas, and a buoyancy-induced flow associated with spatial variations in gas density. The influence of both artifacts is found to be negligible.

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