GRAPHIC SOLUTION 113 



as in Fig. 59. The stresses in the interior members are not affected by 

 the change and will be correctly given by graphic resolution. 



; 2000 G -3000 F +4000 



/ 6 



= 1 7 



b \ 



'I 

 b 



1 | 



t +.-S = l6'-0" 



I 

 I 



B--*- 



V= 3000 



= 2OOO 



~T 



/ 



/ b 



I / -^ 



i n 

 / .c 



10 I 



/ 



/ I 



/ I 



/ I 



-^A *. 

 | V =3000 



Moment Shear 

 2 I 7 



Portql 



1 N 



6 



'71 



CASE I 



Columns Hinqed 



Stress Diagram 



IOOO ZOOO 3000 



Compression 

 Tension 



FIG. 59. 



As before H = 



_ and V = - 



2 



Having the calculated H, H 1 , V , and F 1 , the stresses are calculated by 

 graphic resolution as follows : Beginning at the base of the column A, 

 lay off A-4 = V = 3000 Ibs. acting downward, and A-a = H = 1000 

 Ibs. acting to the right. Then a-i and 4-1 are the stresses in members 

 a-i and 4-1, respectively, heavy lines indicating compression and light 

 lines tension. At joint in auxiliary truss to right of C the stress in i-a 

 is known and stresses in 1-2 and 2-a are found by closing the polygon. 



