JM \OTES ON PLATE-GIRDER DESIGN 



PBOBU MS 



4n. \A-\ ra h of ihr Hangrs ui' tin- gmlrr of il. insist of 



2angie86X6X17.21b6.-KUi.' >.| ins. 



i com i-late I4x| " -:. 



:>iate 14X| " -5.25 



V.T plate 14X| " -:. 

 and i of the \v I, plate 60X|. 



Find the lengths of the rovrr plates wlirji il arts as a part of" a 

 Irrk railway bridge. 



4h. Find the lengths of the rover plates \vhen tlie girder of Prob. 

 4a acts as a part of a through bridge. The < OIK nitrated load P,- 105,000 

 Ibs. The loads being spaced as shown in Fig. 4d. 



ART. 5. RIVET SPACING IN GIRDER FLANGES 



The connect ion between the web and flanges of girders, 

 other composite structures, i> made by means of rivets. 

 Tin >< rivets are spaced with reference to the horizontal 

 component of the stress in the flange, for at the extreme 

 fiber the direction of the stress is horizontal and the 

 maximum shearing unit stresses in the flanges are very small, 

 and hence the horizontal component is the only stress of 

 importance. 



The one important exception to the foregoing is where 

 the girder load i> applied to one of the flanges, here the 

 rivets have to transmit the loading which the girder carries 

 together with the horizontal stress increments between the 

 flanges and web. The exceptional case will receive special 

 consideration. 



The moment of the external forces at any point in a 

 girder equals the moment of the internal stresses, then- 



