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  • Advanced Structural Systems (2) (2)

  • :

  • Fundamental of Structural Stability

  • - :Light and Thin StructuresHeavy and Thick Structures :

  • Light and Thin : .(Specialized Design Capacity) .

  • : - (Very Squat Tube- Short Thick Tube) ( ) (Limit Proportionality) a . P a . (Linear Analysis) . (Bulging) .

  • - (Longer Thick Tube)( ) b . Nonlinear Analysis) (Elastic . (Bowing Sideway) . b c .

  • Buckling is used to denote the dynamic process in which a structure moves from an unstable to another possibly distant stable state( ) (Buckling) . ( )

  • a . . ( Arc-Length Method ) .

  • . (Load- Carrying Capacity) .

  • : -

  • -

  • -

  • Ronan Point

  • - (Exposition Hall in Bucharest)

  • Before collapseAfter collapse COLLAPSE OF EXPOSITION HALL, Bucharest, 1963

  • - (Sun Kink)

  • Soft first story failure

  • Dynamic Buckling of Bridge

  • 2- . (Stable) (Relatively Small Changes) . (Proportional Changes)

  • (Unstable) (Lrage Change) .(Non-Proportional Changes) (Equilibrium State) (Configuration) . ( ) : :

  • :

  • (Small Perturbation Small Disturbance) . (Upseting) .

  • 3-

  • 4- ) .

  • : . .

  • ) .

  • . 2 2 (1-p) p =0 .(2>>0) p ( W1) p =1 .(2=0) p >1 .(2
  • : (real) . (Imaginary) . (zero) .

  • . .

  • ***