Ductility limit prediction using a GTN damage model coupled with localization bifurcation analysis
TypeArticles dans des revues avec comité de lecture
Because the localization of deformation into narrow planar bands is often precursor to material failure, several approaches have been proposed to predict this phenomenon. In this paper, the Gurson–Tvergaard– Needleman (GTN) elastic–plastic–damage model for ductile materials is considered. A large-strain version of this constitutive model is coupled with the Rice localization criterion, which is based on bifurcation theory, to investigate strain localization. The resulting loss of ellipticity condition is then used to determine ellipticiy loss diagrams (ELDs) associated with strain paths that are those typically applied to metals under biaxial stretching. A sensitivity analysis is conducted with respect to the model parameters on a representative selection of ductile materials. The analysis shows that the damage parameters have a significant impact on the predicted ELDs, which confirms the predominant role of damage-induced softening in triggering plastic flow localization with the adopted constitutive description combined with the bifurcation approach. As a consequence of this high sensitivity, it appears that the proper identification of damage parameters is a key issue for accurate plastic flow localization predictions using the GTN model coupled with bifurcation theory. The effect of the dense matrix hardening parameters on the strain localization predictions of the voided aggregate, although found much smaller in the whole, is more noticeable for the plane strain tension loading path or, more generally, when the critical hardening modulus required for localization is not strongly negative.
Showing items related by title, author, creator and subject.
Prediction of strain localization during sheet metal forming using bifurcation analysis and Gurson-type damage MANSOURI, Lotfi; CHALAL, Hocine; ABED-MERAIM, Farid; BALAN, Tudor (E. Oñate, D.R.J. Owen, D. Peric and B. Suárez, 2011)The strain localization phenomenon that may occur during sheet metal forming represents a major cause of defective parts produced in the industry. Several instability criteria have been developed in the literature to predict ...
Plastic Instability Based on Bifurcation Analysis: Effect of Hardening and Gurson Damage Parameters on Strain Localization MANSOURI, Lotfi; CHALAL, Hocine; ABED-MERAIM, Farid; BALAN, Tudor (Trans Tech Publications, 2012)In this work, we propose to couple the Gurson-Tvergaard-Needleman (GTN) model, known for its widespread use to describe damage evolution in metallic materials, to the Rice localization criterion. ...
Prédiction de la localisation par une approche d’endommagement micromécanique couplée à une analyse de bifurcation : application à la mise en forme des tôles MANSOURI, Lotfi; CHALAL, Hocine; ABED-MERAIM, Farid; BALAN, Tudor (Association Française de Mécanique, 2011)Le phénomène de localisation des déformations plastiques, qui apparait lors d’opérations de mise en forme des tôles, représente l’une des principales causes de rebut des pièces produites dans l’industrie. Plusieurs critères ...
Elastic-plastic analyses using the solid-shell finite element SHB8PS and evaluation on sheet forming applications SALAHOUELHADJ, Abdellah; CHALAL, Hocine; ABED-MERAIM, Farid; BALAN, Tudor (Onate, E; Owen, DRJ; Peric, D; Suarez, B, 2011)In this contribution, the formulation of the SHB8PS continuum shell finite element is extended to anisotropic elastic-plastic behavior models with combined isotropic-kinematic hardening at large deformations. The resulting ...
On the implementation of the continuum shell finite element SHB8PS and application to sheet forming simulation SALAHOUELHADJ, Abdellah; ABED-MERAIM, Farid; CHALAL, Hocine; BALAN, Tudor (American Institute of Physics, 2011)In this contribution, the formulation of the SHB8PS continuum shell finite element is extended to anisotropic elastic-plastic behavior models with combined isotropic-kinematic hardening at large deformations. The resulting ...