604 ON THE CALCULATION OF THE EQUILIBRIUM AND STIFFNESS OF FRAMES. 



This is the deflection due to the yielding of all the horizontal pieces. 

 The greater the number of pieces, the less is the importance of the last term. 



Let the inclination of the pieces of the web be a, then the force on a 

 piece between and o is W , . , or 



I a , 



p = f- when x < a. 

 I Bin a 



and 



p' =.=- when x>a. 

 I sin a 



Also 



q'= , . when x < b, 

 I sin a 



q'=j ~ when x > b. 

 I sin a 



If e be the extensibility of a piece of the web, we have to sum WZe'p'tf 

 to get the deflection due to the yielding of the web, 



- 

 sin" a 



