54 



STRESSES IN ROOF TRUSSES 



31. The moving crane trolley will produce maximum moment when 

 it is at the center of the truss, and this case should be investigated in 

 solving the problem. 



10' 15* 



-X, 



1-6 



O 2000 4000 6000 



FIG. 35. 



The method of graphic resolution is commonly used for calculat- 

 ing the stresses in roof trusses and similar structures. For examples 

 of the calculations of stresses in trusses by algebraic resolution, al- 

 gebraic and graphic moments, see Chapter X. 



