On some topics for the numerical simulation of ductile fracture

Authors
Sánchez, Pablo Javier; Oliver, Juan Pablo; Huespe, Alfredo Edmundo
Publication Year
2008
Language
English
Format
article
Status
Published version
Description
In this work, we analyze some aspects of the macroscopic Gurson-Tvergaard-Needleman (GTN) constitutive model when it is addressed to solve ductile fracture problems by means of numerical simulations:(i) The analytical solutions of the material discontinuous bifurcation problem is performed.Closed and exact formulas are obtained. The so determined critical conditions and the developed strain localization mode are afterward studied and compared in crack growth problems. Even when this methodology of analysis is rather standard at the present, the conclusions drawn from this study differ significantly from that obtained with a similar analysis in quasi-brittle fracture problems.(ii) A new very robust numerical integration method for the GTN model, namely the Impl-Ex Method, is proposed. It is a low computational cost algorithm, equivalent to a linear problem per each integration step, with a reasonable precision for engineering purposes. Its accuracy and convergence rate is assessed by means of an error study applied to a ductile fracture test simulation.(iii) A detailed analysis of a plane strain ductile crack growth problem is performed in a material containing two size-scale of voids. In the analysis, particular attention is given to the mesh size dependence and to the coalescence of the larger void.
Fil: Sánchez, Pablo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Fil: Oliver, Juan Pablo. Technical University of Catalonia; España
Fil: Huespe, Alfredo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Subject
Ductile crack growth;
Elasto-plastic porous material
Finite elements; ImplEx algorithm;
Bifurcation and strain localization by void coalescence
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/25388