Identification automatique des paramètres rhéologiques par analyse inverse

Abstract : The improvement of the knowledge of the rheological behavior of materials during the industrial forming processes come necessarily through a better understanding of experimental rheological tests. That is why we have developed an inverse numerical model for the identification of rheological parameters coupling a finite element simulation code of the test with an optimization procedure. The direct model simulates especially axisymmetric torsion, tension and tension-torsion tests. It leads to a more realistic modelling of the test, particularly with regard to the possibility of taking into account the phenomena as the self-heating, the strain localization and the material softening, for which the classical computational assumptions are not more valid. The principle of the parameter identification is based on the determination of the coefficients of the behavior law that minimise a cost function expressing in a least squares sense, the difference between the numerical computation and the experiment. The use of a minimization algorithm of Gauss-Newton has led us to develop a parametric sensitivity analysis using analytical differentiation of the discretized equations defining the simulation model. Thus, the identification software permits to identify automatically and simultaneously all the rheological parameters of a thermo-viscoplastic law as the Norton-Hoff one using a generalized formulation of the material consistency in order to obtain an appropriate description of the competition between the hardening and the softening effects.
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https://pastel.archives-ouvertes.fr/pastel-00733884
Contributor : Adinel Gavrus <>
Submitted on : Monday, October 15, 2012 - 1:44:58 PM
Last modification on : Tuesday, November 20, 2018 - 8:26:01 AM
Long-term archiving on : Wednesday, January 16, 2013 - 2:55:12 AM

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  • HAL Id : pastel-00733884, version 1

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Adinel Gavrus. Identification automatique des paramètres rhéologiques par analyse inverse. Mécanique des matériaux [physics.class-ph]. École Nationale Supérieure des Mines de Paris, 1996. Français. ⟨pastel-00733884⟩

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