Variational phase-field formulation of non-linear ductile fracture

verfasst von
M. Dittmann, F. Aldakheel, J. Schulte, P. Wriggers, C. Hesch
Abstract

Variationally consistent phase-field methods have been well established in the recent decade. A wide range of applications to brittle and ductile fracture problems could already demonstrate the ability to predict complex crack patterns in three-dimensional geometries. However, current phase-field models to ductile fracture are not formulated for both, material and geometrical non-linearities. In this contribution we present a computational framework to account for three-dimensional fracture in ductile solids undergoing large elastic and plastic deformations. The proposed model is based on a triple multiplicative decomposition of the deformation gradient and an exponential update scheme for the return map in the time discrete setting. This increases the accuracy on the entire range of the ductile material behavior encompassing elastoplasticity, hardening, necking, crack initiation and propagation. The accuracy and convergence properties are further improved by the application of a higher order phase-field regularization and a gradient enhanced plasticity model. To account for the ductile behavior at fracture, a model of the critical fracture energy density depending on the equivalent plastic strain is proposed and validated by experimental data.

Organisationseinheit(en)
Institut für Kontinuumsmechanik
Externe Organisation(en)
Universität Siegen
Typ
Artikel
Journal
Computer Methods in Applied Mechanics and Engineering
Band
342
Seiten
71-94
Anzahl der Seiten
24
ISSN
0045-7825
Publikationsdatum
30.07.2018
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Numerische Mechanik, Werkstoffmechanik, Maschinenbau, Physik und Astronomie (insg.), Angewandte Informatik
Elektronische Version(en)
https://doi.org/10.1016/j.cma.2018.07.029 (Zugang: Geschlossen)
 

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