STRESSES IN PINS J 57 



moment is to the right of 3, and is H X y = 200,000 X 1.04 = 208,- 



000 Ib.-in. The force polygon for the vertical forces is given 

 in (h) and the bending moment polygon is given in (i). The maxi- 

 mum vertical bending moment is to the right of 8, and is H X y 

 200,000X142 = 284,000 Ib.-in. The maximum bending moment 

 occurs at and to the right of 4 and 8, and is 351,000 Ib.-in., as shown 

 in (j). 



Shear. The shear is found for both the horizontal and vertical 

 components as in a simple beam, and is equal to the summation of all 

 the forces to the left of the section. The horizontal shear diagram is 

 shown in (k), and the vertical shear diagram is shown in (1). The 

 maximum horizontal shear is between I and 2, and is 165,400 Ibs. The 

 shear between 2 and 3 is 165,400 99,300 = 66,100 Ibs. The maxi- 

 mum vertical shear is between 6 and 7, and is 126,300 Ibs. The result- 

 ant shear between 2 and 3, and 6 and 7, is Vi26,3OO 2 -f- 66,ioo 2 = 

 145,000 Ibs. as in (m), which is less than the horizontal shear between 



1 and 2. The maximum shear therefore comes between i and 2, and is 

 165,400 Ibs. The maximum shearing unit stress is 5750 Ibs. The 

 allowable shearing stress was 9000 Ibs. 



Bearing. The bearing stress in L C7 is 165,650-^-6 X 1.94 = 

 14,300 Ibs. Bearing stress in U i U 2 is 165,400-^- 6 X 1.88=14,600 

 Ibs. Bearing stress in U^ L x is 42,200 -i- 6 X 0.89 = 7900 Ibs. Bearing 

 stress in U L 2 is 107,000^-6 X iA = I2 ,4OO Ibs. The allowable 

 bearing stress was 15,000 Ibs. 



