48 NOTES ON PLATE-GIRDER DESIGN 



as is well known from mechanics, but the proper form 

 of splice should be designed with reference to the distri- 

 bution of these forces. The portion of the web between 

 the flange angles is so near the extreme 



riftf. y fiber that tin- stresses may be assumed to 

 / be horizontal throughout. The flange unit 

 stress has been taken at 10,000 Ibs.; t In- 

 bearing and shearing values for rivets will 

 be taken to correspond to this at 24,000 

 and 12,000 Ibs. per square inch respect- 

 ively, or at 50% more and 25% less than for 

 FIG. 96. tension. The thickness of the splice plates 

 should be sufficient to transmit the maximum 

 possible stresses which can occur at the point of maximum 

 stress in the splice. 



The total stress on the portion of the web betw. n 

 the flange angles = (8" -I") X & X14,667= 44,800 Ibs.; the 

 least that can be used for this part of the splice will he 

 2-7 X| flats for each flange. The net area of these two 

 plates = 4.5 sq.in., while that of the strip of the web = 3.06 

 Ml.in. The bearing value of the rivets is less than that 

 for double shear, hence one rivet is worth 9190 Ibs. at 



43 75 

 the edge of the web plate and 9190x-j^- =8350, an 



average for this part of the splice. The number of rivets 



A A Qf\/\ 



on each side of the splice for splicing the strip = ' Q 

 = 5.37 or 6. 



For the condition of maximum moment there is no 

 shear at the splice and the web stresses are horizontal. 



The number of vertical rows of rivets Is evidently a 



