69 research outputs found

    Maximal monotonicity and convex programming

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    We introduce an explicit constraint qualification condition which is necessary and sufficient for the nondegenerate Lagrange multipliers rule to hold. We compare it with metric regularity conditions and we show that it is strictly weaker than the Slater assumption. Under certain weak smoothness hypotheses, our condition, the Slater condition and the existence of nondegenerate Lagrange multipliers are equivalent. The basic ingredient in the proof of the main result is the theory of maximal monotone operators (Minty's theorem). Another approach using a direct exact penalization argument yields a modified nondegenerate Lagrange multipliers rule involving the positive part of the constraint mapping. Examples and applications to abstract optimal control problems are also indicated

    Optimal design of mechanical structures

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    We prove new properties for the linear isotropic elasticity system and for thickness minimization problems. We also present very recent results concerning shape optimization problems for three-dimensional curved rods and for shells. The questions discussed in this paper are related to the control variational method and to control into coefficients problems

    Generalized bang-bang properties in the optimization of plates

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    For a simly supported plate, we consider two optimization problems: the volume minimization and the identification of a coefficient. Via a transformation recently introduced by the authors, we obtain the optimality conditions in a qualified form, and their analysis yields the bang-bang properties for the optimal thickness. Non consid{\'e}rons pour une plaque pos{\'e}e deux probl{\`e}mes d'optimisation: la minimisation du volume et l'identification d'un coeffcient. Via une transformation r{\'e}cemment introduite par les auteurs, on obtient les conditions d'optimalit{\'e} dans une forme qualifi{\'e}e et leur analyse entraine les propri{\'e}t{\'e}s de boum-boum pour l'{\'e}paisseur optimale

    On the necessity of some constraint qualification conditions in convex programming

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    In this paper, we realize a study of various constraint qualification conditions for the existence of Lagrange multipliers for convex minimization problems in general normed vector spaces, it is based on a new formula for the normal cone to the constraint set, on local metric regularity and a metric regularity property on bounded subsets. As a by-product, we obtain a characterization of the metric regularity of a finite family of closed convex sets

    Optimization of ordinary differential systems with hysteresis

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    We investigate general control problems governed by ordinary differential systems involving hysteresis operators. Our main hypotheses are of continuity type, and we discuss existence results, discretization methods, and approximation approaches

    Sur les arches lipschitziennes

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    We study the Kirchhoff-Love model in the case when the middle curve of the arch has corners. Our approach does not use the Dirichlet principle or the Korn inequality. We propose a variational formulation based on optimal control theory and we obtain explicit formulas for the deformation

    A general asymptotic model for Lipschitzian curved rods

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    In this paper we show that the asymptotic methods provide an advantageous approach to obtain models of thin elastic bodies under minimal regularity assumptions on the geometry. Our investigation is devoted to clamped curved rods with a nonsmooth line of centroids and the obtained model is a generalization of results already available in the literature

    Shape optimization in free boundary systems

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    We analyze existence results in constrained optimal design problems governed by variational inequalities of obstacle type. The main applications that we discuss concern the optimal packaging problem and the electrochemical machining process. Our assumptions, in order to obtain the existence of at least one optimal domain, are just boundedness and uniform continuity (the uniform segment property) for the boundaries of the unknown regions where the free boundary problems are defined. No restrictions on the dimension are imposed
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