10 



INFLUENCE DIAGRAMS 



support of the truss, as a reference point s = oc. For a 

 load on the left of the vertical through E, the moment is 



(25) 



Dividing both members of equation (25) by +00. 

 M. ,Z-( 



(26) 



But, Wi , \-Wi is the expression for vertical shear 



on the right of Wi, and, consequently, practically at the 

 load TFi. 



Tan 04 =-- 

 a 



FIG. 4. 



If CD is laid off equal to S-T-OO =1, the ordinates of the 

 influence diagram represent vertical shears instead of 

 moments. DE drawn through A, which is an infinite 



