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The effective design of viscoelastic dampers as applied to real-world complex engineering structures can be conveniently carried out by using modern multiobjective numerical optimization techniques. The large number of evaluations of the cost functions normally combined with the typically high dimensions of finite element models of industrial structures makes multiobjective optimization very costly, sometimes unfeasible. Those difficulties motivate the study reported in this paper, in which a strategy is proposed consisting in the use of evolutionary algorithms specially adapted to multiobjective optimization of viscoelastic systems, combined with robust condensation and metamodeling. After the discussion of various theoretical aspects, a numerical application is presented to illustrate the use and demonstrate the effectiveness of the methodology proposed for the optimal design of viscoelastic constrained layers.

International audience; The effective design of viscoelastic dampers as applied to real-world complex engineering structures can be conveniently carried out by using modern numerical optimization and/or model updating techniques. However, the large number of exact evaluations of the cost functions, combined with the typically high dimensions of large finite element models of industrial structures incorporating viscoelastic materials, makes the numerical processes very costly, sometimes unfeasible. Those difficulties motivate the study reported herein, in which a general strategy to improve the standard condensation methods by taking into account a priori information of the modifications into the viscoelastic zones is introduced. The proposed method can be used with any condensation procedure, including direct reductions and component mode synthesis.

International audience; The tools of modeling and multicriterion optimization the most employed in the structural dynamics rests on the finite element methods and the genetic algorithms. Although the progress in the data-processing field make it possible to treat models comprising several million degrees of freedom, the costs of calculations especially remain a significant obstacle within the framework of the optimization of complex structures in the presence of uncertainties (geometrical, material) on the parameters of design. It then becomes necessary to reduce the size of the models by using a robust base of Ritz.; Les outils de modélisation et d'optimisation multicritères les plus employés en dynamique des structures reposent sur la méthode des éléments finis et les algorithmes génétiques. Bien que les avancées dans le domaine informatique permettent de traiter des modèles comportant plusieurs millions de degrés de liberté, les coûts de calculs restent un obstacle important dans le cadre de l'optimisation de structures complexes surtout en présence des incertitudes (géométriques, matérielle) sur les paramètres de conception. Il devient alors nécessaire de réduire la taille des modèles en utilisant une base de Ritz robuste.