Stachiw 



No 7740 Gloss 

 ■ 300,000 psi 

 E 8,96 X lO'pji 



Density 139 lb fl^ 



Criticol Pressure of Spheres 

 From Selected Materials 



Fiber Gloss - cr - 75,000 psi, E = 5 x lOl^ psi. 

 Density ^ 130 Ib/ft3 



Titonium - a i 150,000 psi, E = 17.5 X 10* psi. 

 Density = 276 Ib/lt^ 



Aluminum - ct =60,000 psi, E = 10.8 x 101^ psi, 

 Density = 173 Ib^ft^ 



Steel - CT = 150,000 psi, E = 30 x 10* psi. 

 Density = 490 Ib/ft^ 



Acrylic Plastic- a = 11,000 psi, E =450,000 psi. 

 Density =75lb/ft3 



Steel - cr =80,000 psi, E = 30 x 10* psi. 

 Density =490 I b/ft3 



Concrete - C7 = 14,000 psi, E = 3.65 x 10^ psi, 

 Density = 150 Ib/ft^ 



1.2 0.3 0.4 0.5 0.6 0.7 0.! 

 height of Sphere/Weight of Displaced Seawater 



Fig. 1 - Critical pressures of spherical 

 hulls made from selected materials 



0.6 0.8 1.0 1.2 1.4 



Weight of Sphere/Weight of Disploced Seowoter 



Fig. 2 - Critical pressures of concrete spherical hulls 

 as a function of their weight to displacement ratios 



235 



