12 Lander, Stresses in the Main Spars of Monoplanes. 



These values may be used as already indicated {Fig. 6) 

 to draw the moment diagram Blm n op E for the approxi- 

 mately horizontal components of P x P n P . 



Now, at the centres of /;;/, no and pE {Fig. 6) set up 

 ordinates equal to 



— = 2 2_2-= 101 ft. lbs. 



8 8 



and determine the characteristic points h, i,j, k. These 



have been shown to lie above the lines Im, no and pE at 



distances of y$ the maximum parabolic ordinate. 



The moment of the left hand side of B is equal to 

 that induced by the cantilever, and amounts therefore to 

 101 ft. lbs. The true base line u r s t E can now be 

 drawn as before described. 



Next, check the values of P 1 P 2 P S by taking moments 

 about points immediately to the left of C and D respec- 

 tively. 



The moment at a point immediately to the left of C is 

 scaled as 99 ft. lbs. 



• • ^1X1-59 = 3 L2. - 99. 



2 



.*. ^ = 511 lbs. 



The moment immediately to the left of D is scaled as 



1 10 ft. lbs. 



. . / J „X2 , ]6 + r 1 xro2= i -no. 



^ = 407 lbs. 

 Taking moments round E 



n r> n 4© X I K'T^ 



P x 3'3o + P n x 4 17 + P x x 4 44 = 3 ° J 



2 



P t — 304. lbs. 



Comparing these with the values obtained from the 

 equivalent diagram {Fig. 5), it will be seen that the agree- 

 ment is very satisfactory. 



