THE STRESSES IN A STEEL WATER-TOWER. 1 15 



W sec 6 

 tension per lineal inch of joint is T= -- 7 ., where b l is the 



2710^ 



radius of the section in inches. 



The value of T varies from o at / to a maximum at g. It 

 also varies from o when 6 = (cylinder) to infinity when # = 90 



FIG. 21. 



(plane), i.e., the flatter the cone the greater the stress on the 

 circumferential seams. 



To find the stress on a radial joint pass two horizontal planes 

 through the cone at such distances apart that the intercept eh 

 along the elements of the cone equals one inch (Fig. 22). Then 

 the surface ehhe cut from the cone is a tapered ring. This 

 ring is subjected to a normal pressure of p pounds per lineal 

 inch. For p substitute its components p' and p" which are 

 horizontal and along the elements of the cone respectively. 



By reasoning similar to that used in determining the stress on 

 a vertical joint of the cylinder it may be shown that the horizontal 

 component p' produces tension in the ring. Let T be the tension 

 per lineal inch of the radial joint, then T=p'b 1 = pb i sec 6, where 

 b is the radius of the ring in inches. b l secd is represented 

 graphically by the line ab, hence T = pXab. 



The value of T varies from o at / to a maximum at g. 



