Principal Strains (in./in.) 



Figure 104. Effect of ambient temperature on strains in 66-inch-diameter 

 capsule under short-term loading: typical strain on interior 

 surface in the equatorial region. 



Cyclic strains generated by pressure cycling were recorded at 36 

 locations on the acrylic plastic hull. Since all the pressure cycles had 500 psi 

 as the upper pressure limit, the following findings pertain only to pressure 

 cycling of that magnitude. 



1. The principal strains measured at the equator on the external and 

 internal surfaces of the hull during the pressure rise in each hydrostatic cycle 

 were found to be in same range as those measured during a single short-term 

 loading. 



140 



