range of principal strains on the interior surface 

 in the equatorial region of the sphere 



range of principal strains on the exterior surface 

 in the equatorial region of the sphere 



pressurization of the hull to 

 500 psi at 100-psi/min rate 



Notes: 



1. Dimensions of sphere — 66-in. OD x 61-in. ID 



2. Material — grade G Plexiglas 



3. Temperature — 68 to 70°F 



100 150 200 



Time (minutes) 

 Figure 108. Range of strains at the equatorial region of the 66-inch-diameter 

 capsule under sustained hydrostatic loading of 500 psi. 



! i | 



relaxation 









800 psi 



at psi 









700 psi 

 600 psi 

 500 psi 

 400 psi 

 300 psi 



Motes: 





^"~~~ 





^^~~~ 





""~~ 





2. Temperature — 68 to 70°F 



3. Dimensions of sphere — 

 66-in. OD x 61-in. ID 



4. Material— grade G Plexiglas 



■ 





■' 













200 psi 



100 psi 















Time (minutes x 10 ) 



Figure 109. Typical viscoelastic strain on exterior surface of equatorial region 

 in 66-inch-diameter capsule under sustained hydrostatic loadings 

 of different magnitude, and subsequent relaxation. 



144 



