IT, NOTI:S o\ iM..\Ti:-(in;i)];K ni:sii;\ 



pitch pennisMhle were used the stress persquare inch in tin- 

 first cover plate would lx zero at b an<l increase to 16,000 

 :it r. Thi> is highly umlr.-iral.lc. as there would exist in 

 the girder in juxtaposition the an^l<-> \\ith a unit stress 

 of 16,000 ami a cover with an average of 8000 Ibs. The 

 jiirder flange material cannot act in any such way with- 

 out undue I >en ding stresses on thr rivets. 



For thi> important reason cover plates should be made 

 longer than a mere consideration of their relation to the 

 moment polygon would require. The additional length, 

 designated by y in formula (3) required, is a function of 

 the number of rivets necessary t<> equalize the flange 

 unit stress in all the flange material, and may he deter- 

 mined as follows: 



n = number of rows of rivets in the cover plates; 



a = area of flange without the cover plate under 

 consideration, with unit stress ; 



Oi =area of flange, inrludinjr the cover plate under 

 consideration, with unit stress >, : 



p = pitch in inches of the cover plate rivets in 

 each line; 



R*= value of one rivet connecting the cover to the 

 flange; 



yi = additional length of cover plate required at 



each end in ft. = - y\ =' ' ' P ' 



(di a)*i 

 " --P = 



