(f) of about 0.16, at a distance of 2 inches (50 mm) away from the stif- 

 feners . The test specimens had a clear length between stiff eners of 

 127 inches (3220 mm). After accounting for the compHance of the 

 stiff ener, the "actual" length of the cylinder appeared to be about 130 

 inches (3300 mm); hence, the effect of stiffener compliance was small. 



Figure B-16. Local failure of specimen 5-2 (t/D = 0.063, free support). 



To test for possible reduction in implosion strength due to sus- 

 tained loading, the implosion resistance of Group 4 specimens was 

 assumed to be equal to that of the average value of Group 3 specimens; 

 i.e., P. /f = 0.079. Specimen 4-1 was subjected to 85% of this load. 

 After 2.5 hours of load exposure the specimen imploded, which imphed 

 a strength reduction of 15% for a relatively brief period of sustained 



62 



