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Analyses et Identification du comportement mécanique d'aciers à effet TRIP à partir de mesures de champs cinématiques

Abstract : This work aims at understanding the TRIP effect (TRansformation Induced Plasticity) in steels and modeling of their elastoplastic behavior. The work is devoted to analyzing the mechanical behavior of three steels with TRIP effects (304L, 304L-Cu and TRIP 800) and to identifying the material parameters governing their mechanical behavior under monotonic and sequential loading. The final objective of this study is to evaluate the influence of loading paths and of the martensitic transformation. Two elastoplastic models have been analyzed and implemented in the user's material subroutine of the finite element code ABAQUS. The first is the well-known model developed by Lemaitre and Chaboche and taking into account the kinematic hardening without TRIP effect. The second is an elastoplastic constitutive model in all phases (semiphysics developed by Cherkaoui et al.). This model takes into account the characteristics of the different phases and TRIP effect. Several mechanical tests were performed to examine the mechanical behavior of materials under monotonic and sequential loading and in an heterogeneous test. The obtained results are used in experimental databases for the identification of parameters of two models. An inverse identification method was developed and coupled to identify the parameters of two constitutive models. The obtained results show that for multiphase TRIP steels, which contain a small amount of the retained austenite, only a few amount of this unstable austenite will transform to martensite during the loading process. Consequently, there will be no significant changes in the stress-strain curve. In such steels, the application of the model of Lemaître and Chaboche allows predicting the mechanical behavior of TRIP steels (like 304L-Cu and TRIP 800). However, in fully austenitic steels (304L in this study) with the instable austenite phase, the TRIP effect creates a considerable change in the stress-strain curve of uniaxial tensile test. In these steels, the model of Lemaître and Chaboche is not appropriate for modeling the TRIP effect. Therefore, another model that takes into account the TRIP effect (semiphysic model in this work) is recommended.
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https://pastel.archives-ouvertes.fr/pastel-00573718
Contributor : Bagher Mohammad Sadeghi <>
Submitted on : Friday, March 4, 2011 - 1:42:45 PM
Last modification on : Friday, July 17, 2020 - 2:57:08 PM
Long-term archiving on: : Sunday, June 5, 2011 - 2:51:33 AM

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  • HAL Id : pastel-00573718, version 1

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Bagher Mohammad Sadeghi. Analyses et Identification du comportement mécanique d'aciers à effet TRIP à partir de mesures de champs cinématiques. Mécanique des matériaux [physics.class-ph]. Arts et Métiers ParisTech, 2010. Français. ⟨NNT : 2010ENAM0032⟩. ⟨pastel-00573718⟩

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