204 



PRACTICAL STRUCTURAL DESIGN 



Fig. 121 (c) show an efficient and proper detail for the heel of 

 a truss. 



Fig. 122 (a) shows a detail of a knee brace connection to a 

 column which is not uncommon in mill building construction. 



Fig. 122 



This detail is open to the same criticism as the other eccentric 

 connections already discussed. It is especially to be condemned 

 in view of the fact that the knee brace is subject to tension, as 

 well as compression, and when the knee brace is in tension the 

 entire stress must be resisted by two rivet heads. 



Fig. 122 (6) shows the proper detail for this connection. The 

 gauge A, for the rivets connecting the knee to the column flange, 

 should be as small as possible, and the thickness of the connection 

 angles should be such that their moment of resistance at the 

 rivets is equal to the bending moment. This bending moment 

 is equal to one-half the horizontal component of the stress in the 

 knee brace, multiplied by A. 



Fig. 122 (c) is a detail known as a knuckle plate connection. 



