at a ring frame (i.e., at x = ) 



^X°f 



2 \ " ci^ > 



0.91 



l-V 



(17) 



'^y -1-/1 - %MfV,Y, . ^4>M£\ 



2 3 



Ml-l/ 



(18) 



and where 



•5^ = - -2 — is the circumferential stress in an unstiffened cylinder 

 h 



of infinite length, 

 "^xbm ^^ ^^^ longitudinal bending stress in the shell at midbay 



between adjacent ring frames, and 

 ^ (h TsAi ^^ *^^ circumferential membrane stress in the shell at a 



ring frame. 

 These latter two stresses are given by 



xbm 



0.91 



cJu \ll-i/2 



(l-l//2)c( 

 _o(+p + (l-p)Fi _ 



(19) 



/ ^ _ ^4>Mf \ _ (l-l//2)c( 

 \ ' c^u / " c<+p+(l-p)Fi 



(20) 



and where: 



"•eff 

 Lfh 



Jb_ 

 "^Lf 

 24 



