Analytical 



Figure A-5 sinows tlie resulting contour plot of effective stresses for 

 the viewport with the 0-ring. Two stress concentrations are clearly found: 

 (1 ) at the low-pressure face corner, and (2) at the 0-ring groove. Table A-1 

 summarizes the data at the critical locations and indicates that the maximum 

 effective stress value around the 0-ring groove is only about one-half that at 

 the low-pressure face corner. The boundary condition essentially created no 

 difference in the stresses around the 0-ring groove. 



a = (contour number) (0.25) 



Figure A-5. Effective stress contour plot for 90° angle and free boundary 

 condition with 0-ring groove. 



Table A-1. Effective Stress, a^, for Viewport With 0-Ring Groove 



Location 



Boundary Condition | 



Fixed 



Free 



Maximum at 0-ring groove 

 (compressive) 



1.15 



1.41 



Center of low-pressure 

 face (max tension) 



0.728 



no tensile 

 stresses 



Low-pressure face 

 corner (max compressive) 



2.51 



2.58 



39 



