





1 



a =120° 



> 





failure 

 region 





^ 



a =90° 

 a = 60° 



/ 





^--^ 







safe 

 region 





^ 





X 



reV/ // t ~ 







failu 

 zon 



^h-d-H 



Thickness/Minor Diameter Ratio, t/d 

 (a) Compressive region. 



Thickness/Minor Diameter Ratio, t/d 

 (b) Tensile region. 



Figure 19. Design curves for conical acrylic viewports. 



29 



