Figure 16 compares the instantaneous displacements at tlie center of 

 the low-pressure face for both the experimental and analytical work. The 

 two analytical cases (fixed and free) successfully bracketed the experimental 

 results. The smooth surface finish of 32 rms on the viewport flanges, in 

 combination with the liberal use of silicone grease at the viewport-flange 

 interface, resulted in the experimental displacements approaching the analy- 

 tical free boundary condition. 



a= 90° 



T =o+h 

 T° = 70° 



F 





• Experimental 



— -0 Analytical (free) 



D Analytical (fixed) 



1 



\\ 







p = 1 ,000 psi 



mil 



Is, 



\\ 

 \ \ 

 \ ; 



J-. . 











TT •"— dH 



■--, 



-D— -J 





-n- 









0.4 0.8 1.2 1.6 2.0 



Thickness/Minor Dianneter Ratio, t/d 



Figure 16. Comparison of experimental and analytical displacements. 



Discussion 



When comparing the design curves in this report with those in 

 Reference 2, one notices a distinct difference. The curves in Reference 2, 

 based on ultimate strength tests, indicate an exponential increase of strength 



24 



