Browsing by Subject "shell theories"

Now showing 1 - 4 of 4
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    The infinite hierarchy of elastic shell models: some recent results and a conjecture
    (2009-07-09) Lewicka, Marta; Pakzad, Reza
    We summarize some recent results of the authors and their collaborators, regarding the derivation of thin elastic shell models (for shells with mid-surface of arbitrary geometry) from the variational theory of $3$d nonlinear elasticity. We also formulate a conjecture on the form and validity of infinitely many limiting $2$d models, each corresponding to its proper scaling range of the body forces in terms of the shell thickness
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    The matching property of infinitesimal isometries on elliptic surfaces and elasticity of thin shells
    (2008-10-14) Lewicka, Marta; Mora, Maria Giovanna; Pakzad, Mohammad Reza
    Using the notion of \Gamma-convergence, we discuss the limiting behavior of the 3d nonlinear elastic energy for thin elliptic shells, as their thickness h converges to zero, under the assumption that the elastic energy of deformations scales like h^\beta with 2 < \beta < 4. We establish that, for the given scaling regime, the limiting theory reduces to the linear pure bending. Two major ingredients of the proofs are: the density of smooth infinitesimal isometries in the space of W^{2,2} first order infinitesimal isometries, and a result on matching smooth infinitesimal isometries with exact isometric immersions on smooth elliptic surfaces.
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    A note on convergence of low energy critical points of nonlinear elasticity functionals, for thin shells of arbitrary geometry
    (2008-11-26) Lewicka, Marta
    We prove that the critical points of the $3$d nonlinear elasticity functional over a thin shell of arbitrary geometry and of thickness $h$, as well as the weak solutions to the static equilibrium equations (formally the Euler Lagrange equations associated to the elasticity functional) converge, in the limit of vanishing thickness $h$, to the critical points of the generalized von Karman functional on the mid-surface, recently derived in [14]. This holds provided the elastic energy of the $3$d deformations scale like $h^4$ and the magnitude of the body forces scale like $h^3$.
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    Shell theories arising as low energy \Gamma-limit of 3d nonlinear elasticity
    (2008-10-02) Lewicka, Marta; Mora, Maria Giovanna; Pakzad, Mohammad Reza
    We discuss the limiting behavior (using the notion of \Gamma-limit) of the 3d nonlinear elasticity for thin shells around an arbitrary smooth 2d surface. In particular, under the assumption that the elastic energy of deformations scales like h4, h being the thickness of a shell, we derive a limiting theory which is a generalization of the von Karman theory for plates.