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Projecto Avançado de Estruturas Navais. Mestrado em Engenharia Naval. Contents (1). Structural Stability – basic principles Linear approach Non-linear response Non-linear behavior of beam-columns and plates subjected to compressive and combined loading. Influence of initial imperfections
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Projecto Avançado de Estruturas Navais Mestrado em Engenharia Naval
Contents (1) • Structural Stability – basic principles • Linear approach • Non-linear response • Non-linear behavior of beam-columns and plates subjected to compressive and combined loading. • Influence of initial imperfections • Buckling of plates and stiffened plates • Initial imperfections • Residual stresses
Contents (2) • Ultimate strength of plates and stiffened plates • Concept of effective width • Reduction of strength due to imperfections and welding • Residual strength and post buckling behavior of components • Hull girder strength • Linear and Non-linear behavior • Ultimate bending moment • Residual strength
Structural StabilityBasic principles • Equilibrium stability concept • A) Stable • B) Unstable • C) Neutral • Structural limit states • Ultimate limit • Global Failure • Local Failure • Serviceable limit
Structural Stability • Stability and Instability • Ex: Euler column • EI – Structural modulus
Equilibrium state • A) Stable • B) Unstable • C) Stable Transition between differentstates of equilibrium
Types of instability • Bifurcation • Snap-through Euler column P/PE=1+(pq/l)2/8
Non linearity Physical non-linearity Geometrical non-linearity
Material (Plasticity) • Plasticity • Residual stresses
Stability Criteria • Static criteria • Adjacent equilibrium criteria (bifurcation) • Energy criteria (Minimum Potential Energy)
Linear Analysis • Discrete systems • Continuous systems • Aproximate methods • Finite differences method • Engesser-Newmark method • Galerkin method (diferential equations) • Rayleigh-Ritz method (potential energy) • Finite element method
Basic concepts • Effective length • Boundary conditions • Effective width • Boundary conditions • Loading • Manufacturing • Initial geometric imperfections • Residual stresses and welding procedure • Mounting process and restraining • Residual stresses • Welding procedure • Restraining • Physical properties • Loading of the component • Combined loading • Boundary conditions