SECTION XII 



RIVETED JOINTS AND CONNECTIONS 



90. Efficiency of riveted joint. In structural work such as plate 

 girders, trusses, etc., and also in steam boilers, standpipes, and 

 similar constructions, the connections between the various members 

 are made by riveting the parts together. Since the holes for the 

 rivets weaken the members so joined, the strength of the structure 

 is determined by the strength of the joint. 



Failure of a riveted joint may occur in various ways ; namely, by 

 shearing across the rivet, by crushing the rivet, by crushing the 

 plate in front of the rivet, by shearing the plate (that is, pulling 

 out the rivets), or by tearing the plate along the line of rivet holes. 

 Experience has shown, however, that failure usually occurs either 

 by shearing across the rivet or by tearing the plate along the line 

 of rivet holes. 



The strength of any given type of riveted joint is expressed by 

 what is called its efficiency, defined as 



strength of joint 

 Efficiency of riveted joint = 



strength of unriveted member . 



Thus, in Fig. 105, if d denotes the diameter of a rivet and c the 

 distance between rivet holes, or pitch of the rivets, as it is called, 

 the efficiency, <?, of the joint against tearing of the plate along the 

 line of rivet holes is 



c-d 



To determine the efficiency of the joint against shearing across the 

 rivets, let q denote the ultimate shearing strength of the rivet and p 

 the ultimate tensile strength of the plate. Then, for a single-riveted 

 lap joint (Fig. 105), if h denotes the thickness of the plate, the 

 area corresponding to one rivet is he, and the area in shear for 



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