pressure versus change in internal volume for the final pressure loading 
of Model 7A; the insignificant variation from linearity of the curve 
indicates the elastic behavior of the model up to its collapse. 
DISCUSSION OF RESULTS 
Collapse pressures of the six models tested are compared with the 
previous work of Zoelly and Timoshenko, » Baiigandiec and Krenzke® in Table 
5. The theoretical collapse pressures were computed using a Young's modu- 
lus of 30 x 10° psi, and a Poisson's ratio of 0.3 in the elastic range 
and 0.5 in the plastic range. 
The theoretical collapse pressures of those models designed to 
fail in the inelastic range are presented in Table 5. Experimental collapse 
pressures are within 7 percent Ppyp/P, = 0.93) of the pressures of the 
empirical inelastic collapse formula developed at the Model Basin.® As 
expected, these results are consistent with those obtained by Krenzke® for 
aluminum models fabricated in a Similar manner. The inelastic collapse 
pressures of Bijlaard also appear consistent with those inelastic values 
of Krenzke, indicating theoretical collapse pressures that are somewhat 
larger in every case than the respective theoretical collapse pressures 
calculated by the TMB empirical inelastic formula. 
Comparison of the membrane strain sensitivities for Models 4A 
Revised, 1CR Revised, and 7A obtained at the 2-deg longitudinal locations 
with those obtained at the remaining longitudinal locations reveals only 
small variations in membrane deflections. Comparison of the inside and 
the outside strain sensitivities in the longitudinal direction at the 
juncture of the hemisphere with the cylinder does indicate varying degrees 
of bending. As listed in Table 2, the smaller values of spherical thick- 
ness for each model obtained at the 2-deg locations as compared with the 
other locations suggest a reason for such bending. All sphericity 
deviations, also listed in Table 2, were very small, indicating insignifi- 
cant variations from nominal radii. In light of the satisfactory results 
obtained, the deflection and rotation at the boundary of the cylinder and 
the hemisphere appear to have been adequately considered. As indicated in 
Table 5, the maximum deviation between experimental collapse pressure and 
that computed from the TMB empirical inelastic equation was 7 percent 
