PLATE GIRDERS. 583 



(4) By moment of inertia of gross section, 



Rivets Connecting Cover Plates to Flange A ngles. 



(i) and (2). Assuming that all the bending moment is carried by the flanges, or that one- 

 eighth the gross area of the web is available as flange area, 



n-r-d-.\F 



p - ~v^T 



where n = number of rivets on one transverse line. 



r = value of one rivet in single shear or bearing. 

 d = distance back to back of angles. 

 At = total net area of cpver plates in one flange. 



(3) By moment of inertia of net section, 



^nTr 



p -vtt 



where A / = total net area of cover plates in one flange. 



h e = distance between centroids of all cover plates in tension flange and all cover plates 

 in compression flange. 



(4) By moment of inertia of gross section, 



zn-I-r 

 P = V^h. 



where A e = total gross area of cover plates in one flange. 



h e = distance between centroids of all cover plates in tension flange and all cover plates 



in compression flange. 



Web Splice. An ordinary web splice is shown in Fig. 8. Where splice plates are designed 

 to carry part of the moment as well as the shear the splice shown in Fig. 9 is sometimes used. 

 Plates AB and A'B' are assumed to transfer that part of the moment carried by the web, and 

 plate CD to transfer the shear. Two lines of rivets should be used in each section of the web 

 spliced. The number and spacing of rivets in a web splice can be determined only by trial, 

 except when the first method for proportioning the section is used. The rivet most remote from 

 the neutral axis is the most severely stressed. 



(1) Assuming that all the bending moment is carried by the flanges, 



V V 



r = , and 2n = (13) 



2n r 



(2) Assuming that one-eighth the area of web is available as flange area. The stress in the 

 outermost rivet is given by the formula, where M' is moment carried by web, 



. 



(3) By moment of inertia of net section. The stress in the outermost rivet is given by the 

 formula; 



(4) By moment of inertia of gross section. The stress in tho outermost rivet is given by the 

 formula 



For the details of a web splice, see Fig. 16. 



