9 S 



STRESSES IN A TRANSVERSE BENT 



The maximum shear in the leeward column below the knee brace is 

 H 1 = 5600 Ibs. ; the maximum shear above the knee brace is 13,100 Ibs. 

 The maximum moment occurs at the foot of the knee brace and is 

 H 1 x 14 x 12 = 940,800 inch-lbs. 



Case 3. Wind Load Stresses: Wind Horizontal; Columns 

 Fixed at Base. This is Case 2 with the base of the column hinged at 

 the point of contra-flexure. In calculating H and V, Fig. 55, the wind 



5 10 15 20* 



S24O 



Columns Fixed at Base 

 Max-Mom- in Col - = 376320 in- Ibs. 



Wind Lodd Stress Diagram 

 Wind Horizontal 20 Ibs.per sq-fT- 

 15 4000 8000 



16 \ 



-.,, 



Compression 

 Tension 



12 8 4 A 



FIG. 55. WIND LOAD STRESS DIAGRAM, CASE 3. 



above the point of contra-flexure only (see formula (45)) produces 

 stresses in the bent. The value of fixing the columns at the base is 

 seen by comparing the stresses in Case 2 with those in Case 3, both 

 being drawn to the same scale. Maximum shear in the leeward column 

 below the knee brace is H 1 = 4480 Ibs. ; above the knee brace is 5230 

 Ibs. The maximum positive moment occurs at the foot of the knee 

 brace and negative moment at the foot of the column, and is H 1 x 7 

 x 12 = 376,320 inch-lbs. 



