The worst flat spot on each cylinder eventually became the failure 

 location; this location consistently coincided with the wall sections that 

 were thin and somewhat flat initially . 



Radial displacement data, as shown in Figures B-18 and B-19, 

 were plotted at various pressure levels for the test specimens. Data 

 obtained from these plots were used in analyzing the structural 

 behavior. 



Pressure versus w and w relationships are shown in Figures B-20 



through B-22.* The data for w are from the worst flat spot location. 



The w curves come from w data so the maximum pressure for the w 

 m ^ m 



curve (experimental perfect cylinder) cannot exceed P. of the experi- 

 mental out-of-round specimen. 



Radial displacement behavior along the length of the cylinder is 

 shown in Figures B-23 through B-25. The influence of the boundary 

 condition as it is affected by the simple-support and the free-support 

 conditions is vividly seen. 



Radial displacement data for specimens 5-1 and 5-2 were recorded, 

 but meaningful data were not obtained because the end-closures shifted 

 position as the pressure load was increased. The center of the shaft 

 moved, which meant that a common reference point between various 

 pressure levels was not available. 



In Figure B-17, it is observed that the total radial displacement, 

 w„ , is equal to : 



w^ = w + AR. (B-1) 



and 



= w + w^ (B-2) 



m b 



*The analytical curves will be discussed later. 



66 



