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When a structure is put under an increasing compressive load, it becomes unstable and buckling occurs. Buckling is a particularly significant concern in designing shell structures such as aircraft, automobiles, ships, or bridges. This book discusses stability analysis and buckling problems and offers practical tools for dealing with uncertainties that exist in real systems. The techniques are based on two complementary theories which are developed in the text. First, the probabilistic theory of stability is presented, with particular emphasis on reliability. Both theoretical and computational issues are discussed. Secondly, the authors present the alternative to probability based on the notion of 'anti-optimization', a theory that is valid when the necessary information for probabilistic analysis is absent, that is, when only scant data are available. Design engineers, researchers, and graduate students in aerospace, mechanical, marine, and civil engineering who are concerned with issues of structural integrity will find this book a useful reference source.

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Results o f an experimental study o f t h e postbuckling response and f a i l u r e c h a r a c t e r i s t i c s o f 16-and 24-ply o u a s i -i s o t r o p i c and 24-ply o r t h o t r o p i c f l a t rectangular graohite-epoxy p l a t e s loaded i n compression a r e presented. The r a t i o o f f a i l u r e load t o b u c k l i n g load was higher f o r specimens w i t h lower i n i t i a l b u c k l i n g s t r a i n s than f o r specimens w i t h higher i n i t i a l b u c k l i n g s t r a i n s . Some specimens supported more than f i v e times t h e i r i n i t i a l buckling l o a d b e f o r e f a i l i n g . A n a l y t i c a l r e s u l t s obtained from a nonlinear general s h e l l analysis computer code c o r r e l a t e we1 1 w i t h t e s t r e s u l t s up t o f a i l u r e . The specimens f a i l e d along a nodal l i n e o f t h e b u c k l i n o mode i n an induced shear f a i l u r e mode. Some specimens e i t h e r had c i r c u l a r holes o r were subjected t o low-speed impact damage before t e s t i n g . The postbuckling s t r e n g t h o f specimens w i t h high i n i t i a l buckling s t r a i n s i s degraded more by holes and imoact damage than soecimens w i t h lower i n i t i a l b u c k l i n q s t r a i n s . I n t r o d u c t i o n Current metal a i r c r a f t design p r a c t i c e a1 lows some s t r u c t u r a l comoonents (e.g., fuselage and s t a b i l i z e r panels) t o buckle p r i o r t o f a i l u r e under c e r t a i n loading conditions. These components a r e desioned t o c a r r y t h e i r u l t i m a t e load w h i l e i n a postbuckled s t a t e . The use o f advanced-composite m a t e r i a l s i n s i m i l a r postbuckl i n g appl i c a t i o n s could lead t o e f f i c i e n t s t r u c t u r a l designs. Before comp o s i t e s t r u c t u r a l components can be designed f o r these a p p l i c a t i o n s , however, t h e i r postbuckling response and f a i l u r e c h a r a c t e r i s t i c s must be understood w e l l enough t o p r e d i c t t h e i r s t r u c t u r a l behavior. E a r l i e r published work on t h e postbuckl i n g behavior o f composite s t r u c t u r e s (e.g., Refs. 1-4) has focused on a n a l y t i c a l s o l u t i o n s o f c l a s s i c a l o r t h o t r o p i c p l a t e problems. Only a l i m i t e d amount o f data has been published comparing t e s t r e s u l t s w i t h a n a l y t i c a l p r e d i c t i o n s . The compressive s t r e n g t h o f b u c k l i n g -r e s i s t a n t graphiteepoxy laminates has been shown t o be s e r i o u s l y degraded by c i r c u l a r holes (Refs. 5-7) and low-speed impact damage (Refs. 5 , 8 and 9). On t h e o t h e r hand, p r e l iminary t e s t s on graphite-epoxy laminates (Ref. 7) i n d i c a t e t h a t c i r c u l a r holes may have l i t t l e o r no e f f e c t on b u c k l i n g response o r postb u c k l i n g strength. This paper presents r e s u l t s o f a t e s t program t o study the postbuckling response and f a i l u r e c h a r a c t e r i s t i c s o f s...

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