scholarly journals On the stresses induced by flexure in a deep rectangular beam

1934 ◽  
Vol 143 (849) ◽  
pp. 271-284 ◽  
Keyword(s):  
Stress Distribution ◽  
Practical Importance ◽  
Sufficient Accuracy ◽  
Elastic Instability ◽  
Theoretical Interest ◽  
Close Approximation ◽  
Rectangular Section ◽  
Apparent Paradox ◽  
State Of Stress ◽  
Radial Forces

1. When a straight cylindrical rod is bent into a circle by couples applied at its ends, the resulting state of stress is given, with sufficient accuracy for practical purposes, by the well-known theory of St. Venant. In that theory qunatities of the second and higher orders in therms of strain are neglected, and the resulting solution asserts that the stress is purely longitudinal, so that the rod may be thought of as an assembly of cylindrical fibres, each of which behaves independently of its neighbours. It is evident that this description cannot be exact; for a fibre bent into a circle cannot be kept in tension unless radial forces operate to maintain equilibrium, and in the case considered such forces can come only from actions between adjacent fibres. The apparent paradox is explained by the consideration that those action are of the second order in terms of the curvature, and accordingly are neglected in St. Venant's theory. In connection with a certain problem of elastic instability it was thought desirable to attempt a more accurate description for a particular case, namely, a rod of deep and thin rectangular section. It was found that the equations of equilibrium can be integrated independently of any simplifying assumption, and the stress-distribution determined for curvature of any magnitude. The results have no great practical importance, sice they show that St. Venant's theory gives a close approximation to the facts within that range of strains which actual materials can sustain elastically; but they have some theoretical interest, and accordingly are presented in this paper.

scholarly journals Explosion waves and shock waves. IV—Quasi-detonation in mixtures of methane and air

1937 ◽  
Vol 158 (894) ◽  
pp. 348-367 ◽  
Keyword(s):  
Shock Waves ◽  
Detonation Wave ◽  
Practical Importance ◽  
Coal Mines ◽  
Maximum Speed ◽  
Theoretical Interest ◽  
Rapid Motion ◽  
And Shock Waves ◽  
Effects Of Violence

The possibility of detonation in mixtures of methane and air, apart from its theoretical interest, is of practical importance in connexion with the study of explosions in coal mines. Many attempts have been made experimentally to increase the violence of explosion or the intensity of combustion of mixtures of methane and air to see if speeds of flame and effects of violence comparable with those of detonation could be obtained. Mason and Wheeler noted that restrictions in the path of an explosion accelerated the flame, and observed that as the flame of a methane-air mixture passed through the second of two restrictions placed in a 30·5-cm. tube “the development of the detonation wave appeared imminent”. The experiments were continued by Chapman and Wheeler, who obtained a maximum speed of 420 metres per second beyond the restricted section of a tube 5 cm. in diameter. The effect of the restrictions was in their opinion to induce rapid motion in the mixture through which the flame was travelling.

Elastic-Plastic Stress Distribution in a Plastically Anisotropic Rotating Disk

2004 ◽  
Vol 71 (3) ◽  
pp. 427-429 ◽  
Author(s):  
N. Alexandrova ◽  
S. Alexandrov
Keyword(s):  
Stress Distribution ◽  
Yield Criterion ◽  
Plastic Anisotropy ◽  
Rotating Disk ◽  
Flow Rule ◽  
Plane State ◽  
Annular Disk ◽  
Elastic Plastic ◽  
State Of Stress ◽  
Associated Flow Rule

The plane state of stress in an elastic-plastic rotating anisotropic annular disk is studied. To incorporate the effect of anisotropy on the plastic flow, Hill’s quadratic orthotropic yield criterion and its associated flow rule are adopted. A semi-analytical solution is obtained. The solution is illustrated by numerical calculations showing various aspects of the influence of plastic anisotropy on the stress distribution in the rotating disk.

Mechanism, Purpose and the New Freedom

Philosophy ◽  
1934 ◽  
Vol 9 (33) ◽  
pp. 5-18
Author(s):  
William McDougall
Keyword(s):  
Practical Importance ◽  
Theoretical Interest

The problem of the relation between mechanism and purpose is of profound theoretical interest. It is the most fundamental of the great perennially disputed problems. And, unlike some other of the great unsolved problems, it is also of far-reaching and profound practical importance. The kind of answer we give to the question affects in a multitude of ways the conduct of our lives, the form and working of all our institutions, our science, our law, our politics, our economics, our morals, our religion.

scholarly journals On the stresses in the neighbourhood of a circular hole in a strip under tension

1930 ◽  
Vol 229 (670-680) ◽  
pp. 49-86 ◽  
Keyword(s):  
Circular Hole ◽  
Practical Importance ◽  
Infinite Plate ◽  
Two Dimensions ◽  
Theoretical Interest ◽  
Circular Boundary ◽  
Applied Tension ◽  
Circular Holes ◽  
Special Solutions ◽  
Maximum Stresses

The problem of determining the stresses in a plate under tension when the material is pierced by one or more circular holes is one of both theoretical interest and practical importance. Provided that the plate may be regarded as infinitely extended in two dimensions, the solution for a single hole is easily found and is well known. The presence of the hole leads to the occurrence of stresses equal to three times the tension at infinity, these maximum stresses occurring at the edge of the hole and on the diameter perpendicular to the direction of the applied tension. More general stress systems, corresponding to the presence of tractions at the edge of the hole, may be studied by similar methods, not only when the plate is infinite but also when there is a second circular boundary concentric with the first. A number of special solutions for the infinite plate have recently been published by BICKLEY. The solution for a semi-infinite plate with one circular hole was obtained by JEFFREY, using bipolar co-ordinates,§ which may be applied also to the case of an infinite plate pierced by two holes

Reversed Diurnal Blood Pressure Rhythm in Hypertensive Pregnancies

1976 ◽  
Vol 51 (s3) ◽  
pp. 687s-689s ◽  
Author(s):  
C. W. G. Redman ◽  
L. J. Beilin ◽  
J. Bonnar
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Severe Hypertension ◽  
Practical Importance ◽  
Theoretical Interest ◽  
Hypotensive Drug ◽  
Pressure Pattern ◽  
Nocturnal Hypertension ◽  
Hypertension In Pregnancy ◽  
In Pregnancy

1. Reversal of the normal diurnal blood pressure pattern has been demonstrated in women with severe hypertension and renal impairment in pregnancy (pre-eclampsia). 2. Maximum arterial pressure occurred at night in these women. The phenomenon was not due to hypotensive drug therapy or posture. Patients with uncomplicated essential hypertension in pregnancy retained a normal diurnal blood pressure pattern. 3. Nocturnal hypertension in pre-eclampsia is of theoretical interest and practical importance.

scholarly journals Mechanical Stresses Induced by Compression in Castings of the Load-carrying Grate

2016 ◽  
Vol 16 (2) ◽  
pp. 51-54
Author(s):  
J. Słowik ◽  
A. Drotlew ◽  
B. Piekarski
Keyword(s):  
Heat Treatment ◽  
Stress Distribution ◽  
Stress Level ◽  
Stress Transfer ◽  
State Of Stress ◽  
Structure Changes ◽  
Load Carrying ◽  
The Relationship ◽  
Forced Movement

Abstract The main aim of this study was to examine the compression-induced state of stress arising in castings of the guide grates during operation in pusher-type furnaces for heat treatment. The effect of grate compression is caused by its forced movement in the furnace. The introduction of flexible segments to the grate structure changes in a significant way the stress distribution, mainly by decreasing its value, and consequently considerably extends the lifetime of the grates. The stress distribution was examined in the grates with flexible segments arranged crosswise (normal to the direction of the grate compression) and lengthwise (following the direction of force). A regression equation was derived to describe the relationship between the stress level in a row of ribs in the grate and the number of flexible segments of a lengthwise orientation placed in this row. It was found that, regardless of the distribution of the flexible segments in a row, the stress values were similar in all the ribs included in this row, and in a given row of the ribs/flexible segments a similar state of stress prevailed, irrespective of the position of this row in the whole structure of the grate and of the number of the ribs/flexible segments introduced therein. Parts of the grate responsible for the stress transfer were indicated and also parts which play the role of an element bonding the structure.

Enforcement of National Law against Subnational Units in the US

2017 ◽  
Author(s):  
Mark Tushnet
Keyword(s):  
Practical Importance ◽  
State Governments ◽  
Theoretical Interest ◽  
Underlying Theory ◽  
The Us

This chapter is primarily an exposition of the applicable constitutional doctrine on the enforcement of national law against subnational units in the US. It also offers some general observations about the underlying theory of federalism that generates US constitutional doctrine. In the US the question of the enforceability of national law against state governments is a matter of some theoretical interest but relatively little practical importance. The reasons for that situation are a combination of institutional and historical conditions, which the chapter refers to in more detail. For those outside the US, however, the primary message here is that the constitutional doctrine dealing with this sort of enforcement is quite limited in scope and importance, in contrast to its importance in systems whose constitutions create a less centralized version of constitutional federalism.

Plastic deformation of silver chloride. II. Photoelastic study of the internal stresses in glide packets

1949 ◽  
Vol 200 (1060) ◽  
pp. 47-66 ◽  
Keyword(s):  
Plastic Deformation ◽  
Stress Distribution ◽  
Silver Chloride ◽  
Relative Orientation ◽  
Internal Stresses ◽  
Middle Plane ◽  
Pure Bending ◽  
State Of Stress ◽  
Electrical Analogy ◽  
Point To Point

The pattern of birefringence caused by glide in silver chloride is most clearly resolved when the glide planes are observed edge on. It is then possible to sketch the two orthogonal sets of curves giving the directions of polarization at each point of the pattern and, by means of a compensator, to find how the magnitude of the birefringence varies from point to point. The stress distribution can be deduced from the distribution of birefringence, provided that the important influence of the relative orientation of stress axes and crystal axes is taken into account. The state of stress in each plastically deformed grain can be resolved into two parts. (1) Each glide packet is subject to pure bending about two perpendicular axes lying in the glide plane (but with a neutral plane that is not always the middle plane of the packet). This gives stresses that vary discontinuously with a period equal to the spacing of the glide zones. (2) There is also a continuously varying stress distribution which changes only slightly in distances equal to the glide zone spacing. The curvature of the glide packets means either that all the dislocations in one glide zone have the same sign or that positive and negative dislocations are present there in unequal numbers. It is found that, throughout any one grain, the ‘ dislocation charge ’ on each zone (to use an obvious electrical analogy) has the same sign and is never more than about twice the average for the grain.

scholarly journals Stress Distribution in a Plate with a Holes Along the Diagonal Distribution Under Plane Biaxial Load

2020 ◽  
Vol 70 (2) ◽  
pp. 91-100
Author(s):  
Konieczny Mateusz ◽  
Achtelik Henryk ◽  
Gasiak Grzegorz
Keyword(s):  
Numerical Analysis ◽  
Stress Distribution ◽  
Biaxial Loading ◽  
Pure Shear ◽  
The State ◽  
Point Of View ◽  
Shear Load ◽  
Load Case ◽  
State Of Stress ◽  
Biaxial Load

AbstractThe object of the work is numerical analysis of the state of stress in the plate with holes made along its diagonal, which was subjected to a plane load. The plate was subjected to biaxial loading both in the direction of the y axis, i.e. Py = +/-100 kN and the z axis, i.e. Pz = +/-100 kN. It was shown that the highest concentration of reduced stress occurred in a plate with two holes in the case of load in the form of pure shear (Py = -100 kN, Pz = 100 kN). The pure shear load case proved to be the least favourable from the point of view of straining the plate with holes.

Etiopathogenesis of prolonged subfebrile temperatures and their practical significance

1936 ◽  
Vol 32 (12) ◽  
pp. 1429-1438
Author(s):  
V. I. Katerov
Keyword(s):  
Practical Importance ◽  
Practical Significance ◽  
Theoretical Interest ◽  
Great Practical Importance

The question of prolonged subfebrile states (subfebrile conditions) is of enormous theoretical interest and is of great practical importance.

Sign in / Sign up

Export Citation Format

Share Document