I. The influence of stress and strain on the physical properties of matter. Part I. Elasticity— continued . The internal friction of metals

1886 ◽  
Vol 40 (242-245) ◽  
pp. 240-242
Keyword(s):  
Internal Friction ◽  
Physical Properties ◽  
Stress And Strain ◽  
Vibrating Wire ◽  
Coefficient Of Viscosity ◽  
Molecular Friction

An abstract of a paper on this subject has been already published, but the paper itself was withdrawn for the purpose of revision. The fresh experiments which have been for this purpose instituted during the last year were made with improved apparatus, and the coefficient of viscosity of air redetermined, with a view of enabling the author to make more accurate correction for the effect of the resistance of the air. These more recent experiments on the loss of energy of a torsionally vibrating wire, besides confirming the results of the older ones, as far as the latter have been published, have furnished, more or less in addition, the following facts relating to the internal molecular friction of metals.

scholarly journals I. The influence of stress and strain on the physical properties of matter.—Part I. Elasticity (continued).—The effect of magnetisation on the elasticity and the internal friction of metals

1888 ◽  
Vol 179 ◽  
pp. 1-26 ◽  
Keyword(s):  
Internal Friction ◽  
Physical Properties ◽  
Main Part ◽  
Stress And Strain ◽  
Heating Effect ◽  
Vibrating Wire ◽  
The Wire

According to Professor G. Wiedemann, the main part of the internal friction which occurs in a torsionally vibrating wire is due to the rotation of the molecules about their axes, first to this side and then to that, as the wire vibrates to and fro. With this view the author’s own experiments on the internal friction of metals had been so far in accordance that he wished still further to test the matter by investigating the effect of magnetisation on the internal friction. The author has already made some experiments on the effect of magnetisation on the torsional elasticity of metals, but the results of these experiments did not entirely satisfy him, inasmuch as the means of eliminating the heating effect of the magnetising solenoid were imperfect. It is true that the observed changes of temperature wrought by the solenoid were comparatively small, but so also was the apparent alteration of torsional elasticity due to magnetisation; and it seemed, therefore, advisable to reopen the inquiry, and to devise more perfect apparatus, whereby the heating effect above mentioned might be entirely done away with.

III. The influence of stress and strain on the physical properties of matter. Part III. Magnetic induction ( continued ). The internal friction of iron, nickel, and cobalt, studied by means of magnetic cycles of very minute range

1890 ◽  
Vol 47 (286-291) ◽  
pp. 13-14
Keyword(s):  
Internal Friction ◽  
Physical Properties ◽  
Magnetic Induction ◽  
Stress And Strain ◽  
Torsional Oscillations ◽  
Dissipation Of Energy ◽  
Ballistic Method ◽  
Iron Nickel ◽  
Magnetic Cycles ◽  
Molecular Friction

The author has already studied the internal friction of metals by the method of torsional oscillations, and deduced certain simple laws relating thereto. One of the principal objects of the present enquiry was to ascertain how far the dissipation of energy resulting from statical molecular friction which occurs in magnetic cycles of very minute range would be amenable to the laws of dissipation of energy occurring in torsional cycles. The “ballistic” method of observation has been employed, the arrangements being exceedingly sensitive so as to admit of the use of very feeble magnetising forces.

scholarly journals VI. The influence of stress and strain on the physical properties of matter. Part I. Elasticity— continued . The effect of magnetisation on the elasticity and the internal friction of metals

1886 ◽  
Vol 40 (242-245) ◽  
pp. 447-449 ◽  
Keyword(s):  
Internal Friction ◽  
Physical Properties ◽  
Electric Current ◽  
Stress And Strain ◽  
The Wire ◽  
Permanent Rotation ◽  
A Current

The principal object of this investigation was to test the soundness of the view advanced by Professor G. Wiedemann respecting the cause of the internal friction of a torsionally oscillating wire. According to this view the internal friction is mainly due to permanent rotation to-and-fro of the molecules about their axes; it seemed probable, therefore, that experiments on the effects of magnetising a wire either longitudinally with a helix or circularly by passing a current through it would aid in elucidating the matter. In the experiments on the effects of longitudinal magnetisation arrangements were made so that the heat generated in the magnetising helix should not reach the wire, whilst the effect of the heat generated in the wire when an electric current was passed through it was eliminated in a manner which is fully described in the paper.

scholarly journals III. The influence of stress and strain on the physical properties of matter. Part I. Elasticity ( continued ). The effect of change of temperature on the internal friction and torsional elasticity of metals

1886 ◽  
Vol 40 (242-245) ◽  
pp. 343-345 ◽  
Keyword(s):  
Internal Friction ◽  
Physical Properties ◽  
Least Squares ◽  
Logarithmic Decrement ◽  
Stress And Strain ◽  
Method Of Least Squares ◽  
Vibration Period ◽  
Different Temperatures

The author has recently had the honour of presenting to the Society a memoir relating to the internal friction of metals when vibrating torsionally at temperatures ranging from 0° C. to 25° C. He now brings forward results which have been obtained in experiments on the effect of change of temperature on the torsional elasticity and internal friction of metals. The apparatus used and the mode of experimenting are fully described in the paper, so that it will be sufficient, perhaps, to state here that the vibration-period and the logarithmic decrement were very carefully determined at four different temperatures between 0° C. and 100° C., and that the formulæ given below were worked out by the method of least squares; these formulæ are to be found in Tables I and II.

scholarly journals III. The influence of stress and strain on the physical properties of matter. Part III. Magnetic induction

1887 ◽  
Vol 42 (251-257) ◽  
pp. 224-230 ◽  
Keyword(s):  
Physical Properties ◽  
Magnetic Induction ◽  
Central Portion ◽  
Secondary Coil ◽  
Stress And Strain ◽  
Iron Nickel ◽  
Considerable Length ◽  
The Wire ◽  
Effects Of Stress

The author lays before the Society the results of experiments extending over a period of ten years on the effects of stress and strain on the magnetic permeabilities of iron, nickel, and cobalt. Two methods were employed. In one the metal to be tested—usually in the form of wire—was placed with its axis coincident with that of a magnetising solenoid, in most cases of considerable length as compared with the diameter of the wire; round the central portion of the solenoid was wrapped a secondary coil .

scholarly journals IV. The coefficient of viscosity of air

1886 ◽  
Vol 40 (242-245) ◽  
pp. 40-42 ◽  
Keyword(s):  
Internal Friction ◽  
Torsional Vibrations ◽  
Coefficient Of Viscosity ◽  
Cylinders And Spheres

The author has had occasion, whilst investigating the internal friction of metals, to determine the coefficient of viscosity of air. The viscosity of air has already engaged the attention of several distinguished experimenters, amongst others, of G. G. Stokes, Meyer, and Clerk Maxwell. The results obtained, however, differ so widely that it was considered necessary to institute fresh researches into the same subject. The author employed the torsional vibrations of cylinders and spheres, suspended vertically from a horizontal cylindrical bar, and oscillating in a sufficiently unconfined space.

scholarly journals IV. The influence of stress and strain on the physical properties of matter. Part I. Moduli of elasticity─ continued . The viscosity of metals

1885 ◽  
Vol 38 (235-238) ◽  
pp. 42-45
Keyword(s):  
Physical Properties ◽  
Stress And Strain ◽  
Short Account ◽  
William Thomson ◽  
The Wire ◽  
Moduli Of Elasticity

After a short account of the researches of Sir William Thomson and Professor G. Wiedemann, on the loss of energy of a wire when vibrating torsionally, the author proceeds to describe his own experi­ments on the same subject. The wire under examination was clamped at one end into a stout brass block, which was secured to the extremity of a strong iron bracket projecting from a wall.

Electroosmotic introduction of methacrylate polycations to dehydrate clayey soil

2005 ◽  
Vol 42 (3) ◽  
pp. 780-786 ◽  
Author(s):  
Bożena Pączkowska
Keyword(s):  
Internal Friction ◽  
Physical Properties ◽  
High Resistance ◽  
Clayey Soil ◽  
Polymeric Materials ◽  
Friction Angle ◽  
Strength Parameter ◽  
Organic Cations ◽  
Polymeric Additive ◽  
Very High

The results of research on highly swelling and contractible Pliocene clays are presented in this paper. The introduction of the polymer poly(methyl methacrylate) (with pendant chains possessing organic cations (poly-DEAH+Cl–)) into the clay and the dewatering of the clay were performed using the electroosmosis technique. The measurements were made using a simple electroosmosis apparatus equipped with a specially designed anode, with an electric field equal to 0.5 V/cm applied during the process. After the introduction of the polymeric materials into the clay, a more uniform distribution of the water content and a shortening of the dewatering time were observed in the tested samples. In some cases, dehydration in the presence of poly-DEAH+Cl– was four times more effective than dewatering carried out without a polymeric additive. Additionally, as pilot measurements have shown, the introduction of a proper amount of poly-DEAH+Cl– into the host layers of the clay causes: (i) a decrease in the expansion index, EI, of about 60%; (ii) an increase in the strength parameter, Cu (cohesion), of about 50%; (iii) an increase in the internal friction angle, ϕu, of about 100%; and (iv) a very high decrease in soaking. The clay–polymer composite demonstrates high resistance against moisture.Key words: electroosmosis, polymeric additive, electroosmotic dewatering, clay physical properties.

scholarly journals Improvement of Rheological Properties of Soil Structure Based on Lignite Dispersion

2019 ◽  
Vol 8 (11) ◽  
pp. 3700-3704
Keyword(s):  
Physical Properties ◽  
Rheological Properties ◽  
Relative Position ◽  
Time Variation ◽  
Soil Structure ◽  
Constant Strain Rate ◽  
Rheological Parameters ◽  
Stress And Strain ◽  
Relaxation Processes ◽  
Properties Of Soil

This article examines the change in stress and strain media, in particular natural leonardite (brown coal), prepared for grinding and during grinding, due to the restructuring of the material, i.e. changes in the relative position and deformation of the elements of the structure, including at the level of macromolecules that are inert to the deformation and relaxation processes, provide important for the technology to use improved rheological properties of the soil structure based on dispersion of leonardite, information about the physical properties of the material and its structure. The time variation of the stress in an inert-viscous-elastic medium with a constant strain rate depending on the values of the rheological parameters, it is possible to occur by three laws: aperiodic (steady), critical and oscillatory damp

The Importance of the Boundary Layer

1931 ◽  
Vol 35 (244) ◽  
pp. 333-337
Author(s):  
H. Glauert
Keyword(s):  
Boundary Layer ◽  
Internal Friction ◽  
Physical Properties ◽  
Speed Of Sound ◽  
Large Fraction ◽  
Fundamental Importance ◽  
Low Density ◽  
Flow Round ◽  
The Subject ◽  
Indirect Action

When we consider the physical properties of the air, the most noticeable features are its low density and its compressibility, and a student new to the subject might be excused for doubting whether the air were not too light and yielding to support an aeroplane in flight. The air is indeed very compressible, but this property of the air becomes important only when the speed of motion becomes a fairly large fraction of the speed of sound, and in practice its influence is felt only in the behaviour of airscrews with high tip speeds.A more important property of the air is its viscosity or internal friction, and this property is of fundamental importance in flight, either by its direct frictional action or by its indirect action in determining the type of flow round a body. As an example of this indirect action we may consider the lift of a wing.

Sign in / Sign up

Export Citation Format

Share Document