The plastic anisotropy and ductile fracture behavior of an Al–Si–Mg die-cast alloy (AA365-T7, or Aural-2) is probed using a combination of experiments and analysis. The plastic anisotropy is assessed using uniaxial tension, plane-strain tension and disc compression experiments, which are then used to calibrate the Yld2004-3D anisotropic yield criterion. The fracture behavior is investigated using notched tension, central hole and shear specimens, with the latter employing a geometry that was custom-designed for this material. Digital image correlation is used to assess the full strain fields for these experiments. However, fracture is expected to initiate at the through-thickness mid-plane of the specimens and thus it cannot be measured directly from experiments. Instead, the stresses and strains at the onset of fracture are estimated using finite element modeling. The loading path and the resulting fracture locus were found to be sensitive to the yield criterion employed, which underscores the importance of an adequate modeling of plastic anisotropy in ductile fracture studies. Based on the finite element modeling, the fracture locus is represented with three common criteria (Oyane, Johnson–Cook and Hosford–Coulomb), as well as a newly proposed one as the linear combination of the first two. However, beyond that, it is still questionable if all of these experiments are probing the same fracture locus, since the predicted loading paths of notched tension specimens are highly evolving compared to those of central hole and shear ones.
|Number of pages||21|
|Journal||International Journal of Fracture|
|State||Published - Mar 1 2019|
Bibliographical noteFunding Information:
Support of this work from an industrial sponsor is acknowledged with thanks. We also wish to thank Scott Campbell for his help with preparing some of the specimens. Finally, it is a pleasure to acknowledge the help of 2nd Lt. Moritz Dirian, a visiting student from Universität der Bundeswehr, Munich, Germany in this work.
© 2019, Springer Nature B.V.
- Die-cast aluminum alloy
- Ductile fracture
ASJC Scopus subject areas
- Computational Mechanics
- Modeling and Simulation
- Mechanics of Materials