S NOTES ON I'l, IIDER DESIGN 



1 HOBLEMS 



fci. Compute the net area n-|iiinMl in the flanges of a plate girder 

 3<y long and 48" deep out to out of flange angles, when carrying two 

 loads, of 160,000 Ibs. each, spaced .V from the center of the girder and 

 a uniform load of 300 Ibs. |* r linear foot. Assume a web plate of 

 48X|". 



26. Make up a section for the bottom flange of the girder of I 'ml,. 

 2o, using only two angles. 



1r. Make up a section for the bottom flange of the girder of I'n.l>. 

 2a, using i plates and two angles. 



ART. 3. THE DESIGN OF THE CROSS-SECTION OF THE 



FLANGES 



Flanges of plate girders are generally composed of an 

 in pairs or angles in pairs and plates, as is shown in Fig. 

 2o, 26, and 2c. The several parts are connected by rivi -t<. 

 i i tin- rivets are generally punched to a diam- 



eter ft" greater than that of the rivet, or to a diameter of 

 ft" less and sub>e<jueiitlv reamed to ft" greater, or, as in 

 the best class of railway work, drilled to a diameter ft" 

 r than that of the rivet. It is customary in design- 

 ing tension members to allow for a hole J" greater in 

 diameter than that of the rivet, that is, for a J" rivet a 

 hole 1" in diameter should be deducted. The number of 

 holes to be deducted from any tension flange depends on 

 the number of rows of rivets and the spacing of the rivets 

 in the rows. Much might be written on this point, hut 

 only little will be given. 



For the flange shown in a in section, the views of c 

 and d are longitudinal developments of one of the angles 

 showing common methods of grouping the riv. 



