RT Journal Article
T1 New insights into the role of porous microstructure on dynamic shear localization
A1 Ambikadevi Rajasekharan Nair, Vishnu
A1 Nieto Fuentes, Juan Carlos
A1 Marvi Mashhadi, Mohammad
A1 Rodriguez Martinez, Jose Antonio
AB This paper provides new insights into the role of porous microstructure on dynamic shearlocalization. For that purpose, we have performed 3D finite element calculations of electromagneticallycollapsing thick-walled cylinders. The geometry and dimensions of the cylindricalspecimens are taken from the experiments of Lovinger et al. (2015), and the loading andboundary conditions from the 2D simulations performed by Lovinger et al. (2018). The mechanicalbehavior of the material is modeled as elastic-plastic, with yielding described by the vonMises criterion, an associated flow rule and isotropic hardening/softening, being the flow stressdependent on strain, strain rate and temperature. Moreover, plastic deformation is considered tobe the only source of heat, and the analysis accounts for the thermal conductivity of the material.The distinctive feature of this work is that we have followed the methodology developed byMarvi-Mashhadi et al. (2021) to incorporate into the finite element calculations the actual porousmicrostructure of 4 different additively manufactured materials –aluminium alloy AlSi10Mg,stainless steel 316L, titanium alloy Ti6Al4V and Inconel 718– for which the initial void volumefraction varies between 0.001% and 2%, and the pores size ranges from ≈ 6 μm to ≈ 110 μm. Thenumerical simulations have been performed using the Coupled Eulerian-Lagrangian approachavailable in ABAQUS/Explicit (2016), which allows to capture the shape evolution, coalescenceand collapse of the voids at large strains. To the authors’ knowledge, this paper contains the firstfinite element simulations with explicit representation of the material porosity which demonstratethat voids promote dynamic shear localization, acting as preferential sites for the nucleationof the shear bands, speeding up their development, and tailoring their direction ofpropagation. In addition, the numerical calculations bring out that for a given void volumefraction more shear bands are nucleated as the number of voids increases, while the shear bandsare incepted earlier and develop faster as the size of the pores increases.
PB Elsevier
SN 0749-6419
YR 2022
FD 2022-01-01
LK https://hdl.handle.net/10016/34227
UL https://hdl.handle.net/10016/34227
LA eng
NO The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme. Project PURPOSE, grant agreement 758056.
DS e-Archivo
RD 1 sept. 2024