The Theory of Strains in Girders and Similar Structures: With Observations of the Application of Theory to Practice, and Tables of the Strength and Other Properties of Materials

Cover
D. Van Nostrand, 1873 - 632 Seiten
 

Was andere dazu sagen - Rezension schreiben

Es wurden keine Rezensionen gefunden.

Inhalt

CHAPTER II
11
Horizontal strains in braced or thin continuous webs may be neglected
12
FLANGED SEMIGIRDER LOADED AT THE EXTREMITY 16 FlangesAt any cross section the horizontal components of strain in the flanges are eq...
13
Girder of greatest strengthAreas of horizontal flanges should be to each other in the inverse ratio of their ultimate unitstrains
15
girders with parallel flanges is theoretically independent of the depth
16
Maximum fangestrains occur at the weight
23
FLANGED GIRDER SUPPORTED AT BOTH ENDS AND LOADED
29
EXAMPLE 5
31
A concentrated load produces the same strain in the flanges as twice the load uniformly distributed
35
Flangearea of girder of uniform strength when the depth is constant
36
Depth of girder of uniform strength when the flangearea is constant
37
FLANGED GIRDER SUPPORTED AT BOTH ENDS AND TRAVERSED BY A TRAIN OF UNIFORM DENSITY 38 40 50 Passing train of uniform ...
38
Maximum strains in web occur at one end of a passing train
39
Uniform load and passing train shearingstrain
40
Flanges
41
Depth and length for calculation
42
CHAPTER III
43
Transverse strain 57 Neutral surface 58 Neutral axisCentres of strainResultant of horizontal forces in any cross section equals cipher
44
Moment of resistance MBending moment
45
Coefficient of rupture SSemigirder loaded at the extremity 61 Semigirder loaded uniformly 62 Girder supported at both ends and loaded at an interm...
47
Flanges
48
Strength of stones even of the same kind is very variable
51
Strength of similar girdersLimit of length
53
Neutral axis passes through the centre of gravityPractical method of finding the centre of gravity
54
GIRDERS OF VARIOUS SECTIONS 69 Moment of resistance M
56
for sections symmetrically disposed above and below the centre of gravity
57
Two classes of Aanged girders
60
Solid rectangular semigirders
63
Solid round semigirders
66
Flanged semigirders or rectangular tubes taking the web into account
71
Solid round girders
77
Plan of solid rectangular girder of uniform strength when the depth
83
Definitions
88
Lattice web has no theoretic advantage over a single systemPractical
94
Flangestrains derived from a diagram
100
Permanent load Absolute maximum strains
106
WebFlanges
112
GIRDERS SUPPORTED AT BOTH ENDS AND LOADED UNIFORMLY
124
203
140
Example 2Flangestrains nearly uniform with symmetric loading
142
Inverted bowstring or fishbellied girderBow and invert or double bow
149
Web
156
The A truss
157
CHAPTER VIII
164
Flange strains calculated hy moments
182
GIRDERS OP UNIFORM SECTION IMBEDDED AT BOTH ENDS
197
GIRDERS SUPPORTED AT BOTH ENDS AND LOADED UNIFORMLY
203
SEMIGIRDERS LOADED AT THE EXTREMITY VERTICAL
205
Web first method
211
TORSION
212
CHAPTER XIV
224
Crushing strength of castiron
228
VARIOUS METALS
235
Crushing strength of glass
243
Long pillars with flat ends firmly bedded are three times stronger than
249
Hodgkinsons rules for solid or hollow round castiron pillars of medium
256
Steel plates often deficient in uniformity and toughnessPunching
316
Lateral adhesion of the fibres
324
Tensile strength of Roman cementNatural cements generally inferior
330
Tensile strength of glassThin plates of glass stronger than stout bars
337
Closelink chainProofstrain
345
Tensile strength of flat iron and steel wire ropes and flat hemp rope
353
Shearing strength of wroughtiron equals its tensile strength
360
ART PAGE
364
Hodgkinsons formulæ for the increment of length and set of castiron
370
Elastic flexibility of castiron twice that of wroughtironLaw of elasticity
379
ART PAGE
384
A change of temperature of 15º C in castiron and 7 5 C in wroughtiron
390
Punching and drilling tools
396
CHAPTER XXII
411
Rail girders or keelsonsEconomical distance between the crossgirders
417
CHAPTER XXIV
424
CHAPTER VI
426
Effect of centrifugal force
433
CHAPTER XXVII
442
CoversSingle and double covers compared Lapjoint
449
Adhesion of nails and wood screws
462
Effects of longcontinued impact and frequent deflections on castiron bars
470
WROUGHTIRON
478
Gross area available for compressionCompressive working strain
484
Strength and quality of materials should be stated in specificationsProof
491
ART PAGE
498
Singleline lattice bridge 480 feet long
506
Standard working loads for railway bridges of various spans
510
Weight of roofing materials and working loads on roofsWeight of snow
517
CHAPTER XXIX
525
EXAMPLE 6
527
Singleline lattice bridge 480 feet long as in Ex 5 but with higher unit
538
Great economy from high unitstrains in very large girders
546
GIRDERS UNDER 200 FEET IN LENGTH
552
ART PAGE 521 Andersons ruleWeights of lattice and plate girders under 200 feet in length
553
Weights of similar girders under 200 feet span vary nearly as the squares of their lengthsNo definite ratio exists between the lengths and weights of v...
557
CHAPTER XXX
558
does not exceed 700 feet
560
CHAPTER XXXI
561
Introductory
563
Iron and timber combined form a cheap girderTimber should be used in large pieces not cut up into planksSimplicity of design most desirable in gir...
564
Boyne Lattice Bridge general description and detailed weights of girder work
567
Working strains and area of flanges
571
Points of inflexionPressure on points of support
572
Maximum strains in the flanges of the centre span
573
Points of inflexion fixed practicallyDeflectionCamber
574
Experiments on the strength of braced pillars
577
Experiments on the effect of slow and quick trains on deflection
581
Newark Dyke Bridge Warrens Girder
582
Chepstow Bridge Gigantic Truss
583
Crumlin Viaduct Warrens Girder
584
Public Bridge over the Boyne Lattice Girder
585
Bowstring Bridge on the Caledonian Railway
587
Conway Plate Tubular Bridge
588
Brotherton Plate Tubular Bridge
591

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 307 - A great variation exists in the strength of iron bars which have been cut and welded; whilst some bear almost as much as the uncut bar, the strength of others is reduced fully a third.
Seite 470 - The magnitude of the blow in each set of experiments being made greater or smaller, as occasion required. The general result obtained was, that when the blow was powerful enough to bend the bars through one-half of their ultimate deflection (that is to say, the deflection which corresponds to their fracture by dead pressure), no bar was able to stand 4000 of such blows in succession ; but all the bars (when sound) resisted the effects of 4000 blows, etch bending them through one-third of their ultimate...
Seite 472 - In wrought-iron bars no very perceptible effect was produced by 10,000 successive deflections by means of a revolving cam, each deflection being due to half the weight which, when applied statically, produced a large permanent flexure.
Seite 250 - A long, uniform, cast-iron pillar, with its ends firmly fixed, whether by means of discs or otherwise, has the same power to resist breaking as a pillar of the same diameter, and half the length, with the ends rounded or turned so that the force would pass through the axis.
Seite 249 - The strength of a pillar, with one end rounded and the other flat, is the arithmetical mean between that of a pillar of the same dimensions with both ends round, and one with both ends flat. Thus, of three cylindrical pillars, all of the same length...
Seite 307 - ... increased. 64. The density of iron is decreased by being drawn out under a tensile strain, instead of increased, as believed by some. 65. The most highly converted steel does not, as some may suppose, possess the greatest density. 66. In cast-steel the density is much greater than in puddled-steel, which is even less than in some of the superior descriptions of wrought-iron. The foregoing extracts afford the reader but a meagre idea of Mr. Kirkaldy's laborious researches, and the student who...
Seite 470 - A heavy ball was suspended by a wire eighteen feet long from the roof, so as to touch the centre of the side of the bar. By drawing this ball out of the vertical position at right angles to the length of the bar, in the manner of a pendulum, to any required distance, and suddenly releasing it, it could be made to strike a horizontal blow upon the bar; the magnitude of which could be regulated at pleasure, either by varying the size of the ball or the distance from which it was released.
Seite 483 - In a wrought-iron or steel bridge the greatest load which can be brought upon it, added to the weight of the super-structure, should not produce a greater strain on any part of the material than five tons, where wrought-iron is used, or six tons and a half, where steel is employed, per square inch.
Seite 306 - Iron highly heated and suddenly cooled in water is hardened, and the breaking strain, when gradually applied, increased, but at the same time it is rendered more liable to snap. 44. Iron, like steel, is softened, and the breaking strain reduced, by being heated and allowed to cool slowly. 45. Iron subject to the cold-rolling process has its breaking strain greatly increased by being made extremely hard, and not by being "consolidated
Seite 304 - The breaking strain does not indicate the quality, as hitherto assumed. 2. A high breaking strain may be due to the iron being of superior quality, dense, fine, and moderately soft, or simply to its being very hard and unyielding.

Bibliografische Informationen