ing this process of computation, a curve of p vs <^- can be found using 



Equation (51), and a corresponding curve of p^,j, vs '^^ using Equation (49). 



These two curves are then plotted using pressure as the ordinate scale 



and stress intensity as the abscissa scale; the intersection of two curves 



gives the desired inelastic buckling pressure. A detailed discussion of 



this procedure is given in Reference 23 together with some pertinent 



curves for certain coefficients to help facilitate numerical computations. 



ASYMMETRIC BEHAVIOR OF A RING-STIFFENED 

 CYLINDRICAL PRESSURE HULL 



Generally speaking, the three basic modes of collapse for ring- 

 stiffened cylindrical pressure hulls are phenomenologically related to and 

 influenced by instability. Therefore, the real problem of collapse is one 

 in which the stress state and the propensity for instability mutually inter- 

 act. Since premature collapse can be precipitated by instability, it is 

 necessary that efficient design be based on judicious proportionment of 

 the geometry for a given material, so that instability is prevented from 

 occurring until the material is stressed well into the inelastic range. 



Rational methods of analysis are therefore needed to accurately pre- 

 dict the elastic buckling of stiffened cylinders as a starting point from 

 which the more complex interaction problem termed "inelastic buckling" 

 can be solved more readily. Previous authors have suggested that an 

 approach to efficient design may be based on the use of arbitrary factors 

 or margins between buckling and desired maximum strength. Although 

 this appears to be an oversimplification of the problem and represents a 



43 



