Cross-sectional geometry 

 for the cylinders, which 

 includes data on idealized 

 out-of- roundness, is shown in 

 Figures B-26 and B-27 with 

 geometry values given in 

 Table B-8. 



Implosion Results . Table 



B-7 summarizes the results of 



the analyses in terms of 



implosion pressures that were 



controlled by strain failure 



criteria, (P. ) , and stress 

 mi e 



failure criteria, (P. ) . The 

 ' mi a 



implosion strength is given by 

 the nondimensional ratio of 



Tabic B-8. Cross-Sectional Geometry for Cylinders 















Numbers 



Case 



RavgQO 



AR 



tQO 



t60° 



^90° 



of 



No. 



(in.) 



(in.) 



(in.) 



(in.) 



(in.) 



I.obcs, 

 n« 



1 



26.345 







1.31 



- 



- 







2 



26.345 



0.04 



1.31 



1.23 



'- 



lb 



3 



26.015 







1.97 



- 



- 







4 



26.015 



0.04 



1.97 



1.89 



- 



3^ 



5 



26.015 







1.97 



- 



- 







6 



26.015 



0.06 



1.97 



~ 



1.89 



2^' 



7 



25.305 







3.39 



- 









8 



25.305 



0.06 



3.39 



- 



3.31 



2'' 



45° 



'avgQO + ARCOS2 



0° < < 45° 



•(S -45°) 45° < < 90° 



P. /f ' . The analytical implo- 



mi c ^ ^ 



30° 



< 30° 



(0 - 30°) 30° < e < 60° 



See Figure B-26. 

 ■^Scc Figure B-27. 



sion strength is compared to 

 the experimental strength by 

 the ratios shown in the last 

 two columns of Table B-7. 



The experimental specimens were out-of-round cylinders so a true 

 comparison between analysis and experiment is only for out-of-round 

 cylinder cases (Cases 2, 4, 6, and 8). The average ratio of strain- 

 controlled implosion strength to experimental implosion strength was 

 0.89 and for stress -controlled implosion strength to experimental implo- 

 sion strength was 0.93. 



The stress criterion failure mode predicted implosion with better 

 accuracy than the strain criterion method. Looking more closely at 

 individual cases. Case 2 was an instability failure mode and analysis 

 predicted implosion 15% lower than experimental. Cases 4, 6, and 8 

 were material failure modes, and analysis predicted implosion only 4% 

 lower than experimental. 



76 



