44 



STRESSES IN FRAMED STRUCTURES 



toward the ends of the stress lines and toward the joints, respectively, 

 and tension is indicated by arrows acting away from the ends of the 

 stress lines and away from the joints, respectively. The first time a 

 stress is used a single arrow, and the second time the stress is used a 

 double arrow is used to indicate direction. The stress diagram in (k) 

 Fig. 27 is called a Maxwell diagram or a reciprocal polygon diagram. 

 The notation used is known as Bow's notation. The method of graphic 

 resolution is the method most commonly used for calculating stresses in 

 roof trusses and simple framed structures with inclined chords. 



Algebraic Moments. The reactions may be found by applying 

 the fundamental equations of equilibrium to the structure as a whole. 

 In the truss in (a) Fig. 28 by taking moments about the right reaction 

 we have 



A RB 



R|2 



(0 



FIG. 28. 



