Identification of heterogeneous elastoplastic materials by Constitutive Equation Gap Method

Tarik Madani (1, 2) , Yann Monerie (1, 2) , Stéphane Pagano (3, 2) , Céline Pélissou (4, 2) , Bertrand Wattrisse (1, 2)

1 ThM2 - ThermoMécanique des Matériaux
2 MIST - Laboratoire de micromécanique et intégrité des structures
3 M3 - Mathématiques et Modélisations en Mécanique
4 IRSN - Institut de Radioprotection et de Sûreté Nucléaire

A strategy for identifying the shape and the parameters of elastoplastic laws in heterogeneous material is proposed here. It allows the local characterization of both mechanical properties and stress fields. This method relies on the constitutive equation gap principles and on the measurement of overall loads and strain fields. These fields are obtained by the numerical differentiation of displacement fields measured by Digital Image Correlation. The identification method is based on the iterative minimization of an energy norm involving the secant elastoplastic tensor. We propose here to characterize the robustness of the method and its stability (to noise, initial parameters and mesh) on numerical data sets obtained on numerically-deformed images. Finally, we illustrate the ability of the method to identify the local material properties of a heterogeneous material on real experimental data.

Mots clés: Digital Image Correlation; Identification; Constitutive Equation Gap; Elastoplasticity

Domaines: Mécanique des matériaux [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Mécanique des solides [physics.class-ph]; Mécanique des structures [physics.class-ph]

Tarik Madani, Yann Monerie, Stéphane Pagano, Céline Pélissou, Bertrand Wattrisse. Identification of heterogeneous elastoplastic materials by Constitutive Equation Gap Method. iDICs 2016 Conference and Workshop, Nov 2016, Philadelphie, United States. ⟨hal-02081150⟩