596 



THE DESIGN OF STEEL DETAILS. 



CHAP. XVII. 



Note. In the analysis above it was assumed that the beam connections were bolted and 

 that the bolts would not transmit tension in the direction of their length. If the connection is 

 bolted or riveted rigidly so that the bolts or rivets may transmit tension (rivets should never 

 transmit tension) in the direction of their length, the resisting moment thus developed will de- 

 crease the shearing stresses on the rivets in the connection due to bending moment. 



o -woo 8000 leooo 



Equilibrium Polygon 



FIG. 15. STRESSES IN AN ECCENTRIC RIVETED CONNECTION. 



Web Splice. The plate girder shown in Fig. 1 6 is to be spliced at a section where the bending 

 moment is 1,667,000 in.-lb. and the shear is 165,000 Ib. 



Solution. The method which assumes that one-eighth the area of the web is available as 

 flange area will be used. The formula for stress in the outermost rivet is 



(H) 



1 \ 4U / \ <2*JU~ / 



V = total shear at the section. 



M' = moment carried by web. 



2 = number of rivets on one side of the splice. 



22d 2 = the sum of the squares of the distances of the rivets, on one side of the splice, from the 



neutral axis. 



The joint must first be designed and then investigated. The number of rivets required is 

 several rivets in excess of the number required to carry the direct shear. The number of % in. 

 rivets required for shear alone is determined by bearing on the Yi in. web plate, and is 



V 164,000 



2n = = - = 15.6, (Table 114). 

 r 10,500 



I 



A joint with 17 rivets spaced as shown in Fig. 16 will be assumed. An odd number of rivets 

 simplifies the calculation. 



V = 165,000 ib. 



M' = 1, 667.000.X 3.00 -r- 12.50 = 400,000 in.-lb. 

 2n = 17. 

 d n = 16 in. 



= 2(2 2 -f 4 2 + 6 2 + 8 2 + I0 2 + I2 2 + I4 2 + i6 2 ) = 1632 in. 2 



