New insights into the role of porous microstructure on dynamic shear localization Articles uri icon

publication date

  • January 2022

start page

  • 1

end page

  • 29


  • 148

International Standard Serial Number (ISSN)

  • 0749-6419

Electronic International Standard Serial Number (EISSN)

  • 1879-2154


  • This paper provides new insights into the role of porous microstructure on dynamic shear
    localization. For that purpose, we have performed 3D finite element calculations of electromagnetically
    collapsing thick-walled cylinders. The geometry and dimensions of the cylindrical
    specimens are taken from the experiments of Lovinger et al. (2015), and the loading and
    boundary conditions from the 2D simulations performed by Lovinger et al. (2018). The mechanical
    behavior of the material is modeled as elastic-plastic, with yielding described by the von
    Mises criterion, an associated flow rule and isotropic hardening/softening, being the flow stress
    dependent on strain, strain rate and temperature. Moreover, plastic deformation is considered to
    be 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 by
    Marvi-Mashhadi et al. (2021) to incorporate into the finite element calculations the actual porous
    microstructure of 4 different additively manufactured materials –aluminium alloy AlSi10Mg,
    stainless steel 316L, titanium alloy Ti6Al4V and Inconel 718– for which the initial void volume
    fraction varies between 0.001% and 2%, and the pores size ranges from ≈ 6 μm to ≈ 110 μm. The
    numerical simulations have been performed using the Coupled Eulerian-Lagrangian approach
    available in ABAQUS/Explicit (2016), which allows to capture the shape evolution, coalescence
    and collapse of the voids at large strains. To the authors" knowledge, this paper contains the first
    finite element simulations with explicit representation of the material porosity which demonstrate
    that voids promote dynamic shear localization, acting as preferential sites for the nucleation
    of the shear bands, speeding up their development, and tailoring their direction of
    propagation. In addition, the numerical calculations bring out that for a given void volume
    fraction more shear bands are nucleated as the number of voids increases, while the shear bands
    are incepted earlier and develop faster as the size of the pores increases.


  • Mechanical Engineering


  • adiabatic shear bands; porous microstructure; thermal softening; microstructural softening; printed metals