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
 

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
Web shearing strain
24
Flanges
41
Coefficient of rupture S Semigirder loaded at the extremity
47
388
49
Strength of similar girdersLimit of length
53
Solid square semigirders with one diagonal verticalSolid square girders
64
Square tubes with vertical sides
70
Elevation of solid rectangular girder of uniform strength breadth constant
79
ART PAGE
81
Transverse strength of thick castings much less than that of thin castings
86
Web
92
Permanent loadAbsolute maximum strains
106
WebFlanges
112
Web second method
118
INTERMEDIATE POINT
122
CHAPTER VII
129
71
132
Calculation by moments
135
Example 2Flangestrains nearly uniform with symmetric loading
142
Inverted bowstring or fishbellied girderBow and invert or double bow
149
Flanges
157
Flanges
160
CHAPTER VIII
164
constant
169
SEMIGIRDERS OF UNIFORM SECTION LOADED AT THE EXTREMITY
171
Central deflection of a girder loaded uniformly equals fiveeighths of
178
ART PAGE
187
166
189
Three spans loaded uniformly
193
CHAPTER X
200
Web the length containing an even number of bays
203
CHAPTER XI
209
Moment of resistance of torsion
215
ART PAGE
222
Crushing strength of castiron
228
VARIOUS METALS
235
Crushing strength of glass
243
Web first method
244
Pillars divided into three classes according to length
248
Experimental method of finding the points of inflexionThe depth of
249
Strength of similar long pillars is as their transverse area
252
and H shaped pillars
325
117
327
Tensile strength of Roman cementNatural cements generally inferior
330
Tensile strength of Keenes Parian and Medina cements
333
Strength and weight of cordageEnglish ruleFrench rule
340
Tensile strength
345
Long openlink chainAdmiralty proofstrainTrinity proofstrain
346
Tensile strength of flat iron and steel wire ropes and flat hemp rope
353
Shearing strength of wroughtiron equals its tensile strength
360
Hodgkinsons formulæ for the increment of length and set of castiron
370
Elastic flexibility of castiron twice that of wroughtironLaw of elasticity
379
TEMPERATURE
384
Strains at centre of girder
388
A change of temperature of 15 C in castiron and 7 5 C in wroughtiron
390
Punching and drilling tools
396
ART PAGE
402
CHAPTER XXII
411
Rail girders or keelsonsEconomical distance between the crossgirders
417
CHAPTER XXIV
424
Effect of centrifugal force
433
CHAPTER XXVII
442
CoversSingle and double covers comparedLapjoint
449
EXAMPLE 5
453
Girdermakers Boilermakers and Shipbuilders rules for rivetingChain
455
Adhesion of nails and wood screws
462
Various economical arrangement of tensionjoints
465
Effects of longcontinued impact and frequent deflections on castiron bars
470
Net area only available for tensionAllowance for the weakening effect
476
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
Weights of large girders do not vary inversely as their depth
542
Error in assuming the permanent load uniformly distributed in large girders
550
CONCLUDING OBSERVATIONS
561
WROUGHTIRON PILLARS
570
Working strains and area of flanges
571
Bowstring Bridge on the Caledonian Railway
587
Prolonged fusion within certain limits increases the strength and density
590
454
599
Brotherton Plate Tubular Bridge
616
Tensile strength of thick castings of highly decarbonized iron greater than
617

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

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 306 - In screwed bolts the breaking strain is found to be greater when old dies are used in then- formation than when the dies are new, owing to the iron becoming harder by the greater pressure required in forming the screw thread when the dies are old and blunt than when new and sharp.
Seite 249 - Thus, of three cylindrical pillars, all of the same length and diameter, the first having both its ends rounded, the second with one end rounded and one flat, and the third with both ends flat, the strengths are as 1, 2, 3, nearly.
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 431 - Ibs. is sufficient to produce fracture if passed over them at the rate of 30 miles an hour. It also appeared that when motion was given to the load, the points of greatest deflection, and, still more, of the greatest strains, did not remain in the centre of the bars, but were removed nearer to the remote extremity of the bar. The bars, when broken by a travelling load, were always fractured at points beyond their centres, and often broken into four or five pieces, thus indicating the great and unusual...
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 361 - ... for copper plates. Multiply the constant number by the given diameter in inches, and by the thickness in inches ; the product is the pressure in pounds, which will be required to punch a hole of a given diameter, through a plate of a given thickness. It was observed that, duration of pressure lessened considerably the ultimate force necessary to punch through metal, and that the use of oil on the punch reduced the pressure about eight per cent. A drawing of the experimental lever and apparatus...

Bibliografische Informationen