An electro-elastic phase-field model for nematic liquid crystal elastomers based on Landau-de-Gennes theory

Basing on Landauâ€“de Gennes theory, this study investigated the chiral configurations of nematic liquid crystals confined to cylindrical capillaries with homeotropic anchoring on the cylinder walls. When the elastic anisotropy (L2/L1) is large enough, a new structure results from the convergence of two opposite escape directions of the heterochiral twist and escape radial (TER) configurations. The new defect presents when L2/L1â‰¥7 and disappears when L2/L1<7. The new structure possesses a heterochiral hyperbolic defect at the center and two homochiral radial defects on both sides. The two radial defects show different chiralities.

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A cohesive phase-field model for ductile fracture

10.26226/morressier.5f5f8e69aa777f8ba5bd5fce ◽

2020 ◽

Author(s):

Brandon Talamini

Keyword(s):

Ductile Fracture ◽

Phase Field ◽

Field Model ◽

Phase Field Model

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MARMOT Phase-Field Model for the U-Si System

10.2172/1389724 ◽

2016 ◽

Author(s):

Larry Kenneth Aagesen ◽

Daniel Schwen

Keyword(s):

Phase Field ◽

Field Model ◽

Phase Field Model

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Phase-field modeling of grain evolutions in additive manufacturing from nucleation, growth, to coarsening

npj Computational Materials ◽

10.1038/s41524-021-00524-6 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Min Yang ◽

Lu Wang ◽

Wentao Yan

Keyword(s):

Additive Manufacturing ◽

Phase Field ◽

Field Model ◽

Three Dimensional ◽

Phase Field Model ◽

Nucleation Theory ◽

Experimental Result ◽

Classical Nucleation Theory ◽

Validation Experiment ◽

Powder Particles

AbstractA three-dimensional phase-field model is developed to simulate grain evolutions during powder-bed-fusion (PBF) additive manufacturing, while the physically-informed temperature profile is implemented from a thermal-fluid flow model. The phase-field model incorporates a nucleation model based on classical nucleation theory, as well as the initial grain structures of powder particles and substrate. The grain evolutions during the three-layer three-track PBF process are comprehensively reproduced, including grain nucleation and growth in molten pools, epitaxial growth from powder particles, substrate and previous tracks, grain re-melting and re-growth in overlapping zones, and grain coarsening in heat-affected zones. A validation experiment has been carried out, showing that the simulation results are consistent with the experimental results in the molten pool and grain morphologies. Furthermore, the grain refinement by adding nanoparticles is preliminarily reproduced and compared against the experimental result in literature.

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