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Micromechanical modeling approach to derive the yield surface for BCC and FCC steels using statistically informed microstructure models and nonlocal crystal plasticity
N. Vajragupta, S. Ahmed, M. Boeff, A. Ma, A. Hartmaier.
Physical Mesomechanics, 20, 100-108, (2017)
Abstract
In order to describe irreversible deformation during metal forming processes, the yield surface is
one of the most important criteria. Because of their simplicity and efficiency, analytical yield functions along
with experimental guidelines for parameterization become increasingly important for engineering applications.
However, the relationship between most of these models and microstructural features are still limited. Hence,
we propose to use micromechanical modeling, which considers important microstructural features, as a part of
the solution to this missing link. This study aims at the development of a micromechanical modeling strategy to
calibrate material parameters for the advanced analytical initial yield function Barlat YLD 2004-18p. To accom-
plish this, the representative volume element is firstly created based on a method making use of the statistical
description of microstructure morphology as input parameter. Such method couples particle simulations to
radical Voronoi tessellations to generate realistic virtual microstructures as representative volume elements.
Afterwards, a nonlocal crystal plasticity model is applied to describe the plastic deformation of the representa-
tive volume element by crystal plasticity finite element simulation. Subsequently, an algorithm to construct the
yield surface based on the crystal plasticity finite element simulation is developed. The primary objectives of
this proposed algorithm are to automatically capture and extract the yield loci under various loading conditions.
Finally, a nonlinear least square optimization is applied to determine the material parameters of Barlat YLD
2004-18p initial yield function of representative volume element, mimicking generic properties of bcc and fcc
steels from the numerical simulations.
DOI: 10.1134/S1029959917030109
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