2.3.3.3.154. NXmicrostructure_gragles_config

Status:

application definition, extends NXobject

Description:

Application definition for configuring GraGLeS. ...

Application definition for configuring GraGLeS.

GraGLeS is a continuum-scale model for shared-memory-parallelized simulations of the isothermal evolution of 2D and 3D grain boundary networks with a level-set approach. CPU parallelization is achieved with OpenMP.

The code has been implemented by C. Mießen in the group of G. Gottstein at the Institute für Metallkunde und Metallphysik, RWTH Aachen University.

Details of the model are summarized in C. Mießen.

Symbols:

No symbol table

Groups cited:

NXcs_profiling, NXentry, NXmicrostructure, NXobject, NXprogram, NXserialized, NXuser

Structure:

ENTRY: (required) NXentry

definition: (required) NX_CHAR ⤆

Obligatory value: NXmicrostructure_gragles_config

simulation_identifier: (required) NX_UINT

Simulation ID as an alias to refer to this simulation.

description: (required) NX_CHAR

Discouraged free-text field to add further details to the computation.

start_time: (required) NX_DATE_TIME ⤆

end_time: (recommended) NX_DATE_TIME ⤆

profiling: (optional) NXcs_profiling

USER: (optional) NXuser ⤆

program1: (required) NXprogram

program_name: (required) NX_CHAR

@version: (required) NX_CHAR

@url: (recommended) NX_CHAR

environment: (optional) NXobject

Programs and libraries representing the computational environment

programID: (required) NXprogram

program: (required) NX_CHAR ⤆

@version: (required) NX_CHAR ⤆

discretization: (required) NXmicrostructure

edge_length: (required) NX_FLOAT {units=NX_LENGTH}

The formulation of mean curvature flow in the GraGLeS model is scale invar ...

The formulation of mean curvature flow in the GraGLeS model is scale invariant. Therefore, the discretization has to be scaled to the actual physical length of the simulation domain (ve, ROI). For GraGLeS the discretization is always a square or cubic axis-aligned bounding box with a regular tiling into material points (either squares or cubes respectively).

Edge_length is the length of the entire domain along its edge not the length of the Wigner-Seitz cell about each material point!

grid: (required) NXserialized

From which file should the microstructure be instantiated.

type: (required) NX_CHAR ⤆

path: (required) NX_CHAR ⤆

algorithm: (required) NX_CHAR ⤆

checksum: (required) NX_CHAR ⤆

sampling: (required) NXobject

Configuration when snapshots of the system should be taken. ...

Configuration when snapshots of the system should be taken.

Keep in mind that essentially geometry snapshot data store the polylines and polyhedra of all grains which can take substantial disk space.

system: (required) NX_UINT {units=NX_UNITLESS}

Generate a snapshot of the properties of the grains to follow ...

Generate a snapshot of the properties of the grains to follow the evolution of the microstructure every \(n\)-th iteration. Setting zero causes that no property snapshots are taken.

geometry: (required) NX_UINT {units=NX_UNITLESS}

Generate a snapshot of the geometry of the entire grain boundary network ...

Generate a snapshot of the geometry of the entire grain boundary network every \(n\)-th iteration. Setting zero instructs to store no geometry data.

simulation_control: (required) NXobject

Configuration when the simulation should be stopped in a controlled manner. ...

Configuration when the simulation should be stopped in a controlled manner. Whichever criterion is fulfilled first triggers the controlled stop of and termination of GraGLeS.

number_of_grains: (required) NX_UINT {units=NX_UNITLESS}

The simulation stops if the total number of grains ...

The simulation stops if the total number of grains becomes smaller than this criterion.

number_of_iterations: (required) NX_UINT {units=NX_UNITLESS}

The simulation stops if more iterations than this criterion have been computed.

numerics: (required) NXobject

Configuration of numerical details of the solver.

convolution_mode: (required) NX_CHAR

Which type of convolution kernel and model is used. ...

Which type of convolution kernel and model is used.

Any of these values: gaussian | laplace | laplace_ritchardson

time_slope: (required) NX_FLOAT {units=NX_ANY}

Constant to calibrate the real time scaling of the simulation.

grid_coarsement: (required) NXobject

Configuration of the grid coarsement algorithm whereby the representation ...

Configuration of the grid coarsement algorithm whereby the representation of the system is continuously rediscretized such that on average grains are discretized with discretization many material points along each direction.

Grid coarsement can reduce the computational costs substantially although it cannot be ruled out completely that the rediscretizing may have an effect on the system evolution. Without grid coarsement the total number of material points to consider stays the same throughout the simulation.

discretization: (required) NX_UINT {units=NX_UNITLESS}

Number of material points along each direction to discretize the ...

Number of material points along each direction to discretize the average grain. The larger this value is chosen the finer the curvature details are that can be resolved but also the longer the simulation takes.

is_active: (required) NX_BOOLEAN

If true grid coarsement is active, otherwise it is not.

gradient: (required) NX_FLOAT {units=NX_DIMENSIONLESS}

Fraction how strongly the number of grains has to reduce ...

Fraction how strongly the number of grains has to reduce to trigger a grid coarsement step in an iteration.

grain_boundary_mobility: (required) NXobject

Physically-based model of the assumed mobility of the grain boundaries. ...

Physically-based model of the assumed mobility of the grain boundaries.

Grain boundary mobility is not an intrinsic property of a grain boundary but system-dependent especially as grain boundaries in reality are decorated with defects as a consequence of which the actual mobility is a combination of the mobility of the individual defects and the attached boundary patches. Grain boundaries have different degrees of microscopic freedom. Therefore, their mobility follows a distribution.

model: (required) NX_CHAR

Fundamental model how :math:`m` is assumed a function of the disorientatio ...

Fundamental model how \(m\) is assumed a function of the disorientation angle \(\Theta\).

Obligatory value: rollett_holm

m_null: (required) NX_FLOAT {units=NX_ANY}

The assumed mobility :math:`m_0` of the fastest grain boundary in the syst ...

The assumed mobility \(m_0\) of the fastest grain boundary in the system at the assumed temperature. GraGLeS was developed for modelling isothermal annealing.

c_one: (required) NX_FLOAT {units=NX_DIMENSIONLESS}

Mobility scaling factor \(c_1\). Typically 0.99 or higher but not one.

c_two: (required) NX_FLOAT {units=NX_UNITLESS}

Mobility scaling factor \(c_2\). Typically 5.

c_three: (required) NX_FLOAT {units=NX_UNITLESS}

Mobility scaling factor \(c_3\). Typically 9.

grain_boundary_energy: (required) NXobject

Physically-based model of the assumed grain boundary surface energy. ...

Physically-based model of the assumed grain boundary surface energy.

Like for the grain boundary mobility, defects cause a distribution of energies for the patches of which the boundary is composed. In practice a too complicated dependency of the energy and mobility model is observed as a function of the type and chemical decoration of the defects. Therefore, simplifying assumptions are typically made.

type: (required) NX_CHAR

Fundamental type of assumption if energies are considered isotropic or not ...

Fundamental type of assumption if energies are considered isotropic or not.

Any of these values: isotropic | anisotropic

model: (required) NX_CHAR

Fundamental model how :math:`\gamma` is assumed a function of the disorien ...

Fundamental model how \(\gamma\) is assumed a function of the disorientation angle \(\Theta\).

Obligatory value: read_shockley

gamma: (required) NX_FLOAT {units=NX_ANY}

Mean grain boundary surface energy that is assumed a function of the ...

Mean grain boundary surface energy that is assumed a function of the disorientation angle \(\Theta\) of the adjoining grains \(\gamma(\Theta)\). This value factorizes the curvature_driving_force model.

curvature_driving_force: (required) NXobject

A continuum-scale curvature of an interface causes the interface to ...

A continuum-scale curvature of an interface causes the interface to migrate towards the center of the curvature radius.

is_active: (required) NX_BOOLEAN

If true the curvature_driving_force is considered, otherwise it is not.

stored_elastic_energy: (required) NXobject

A continuum-scale difference of the stored elastic energy in dislocation ...

A continuum-scale difference of the stored elastic energy in dislocation configurations across a grain boundary can exert a driving force on the grain boundary such that the boundary migrates into the volume with the higher stored elastic energy.

is_active: (required) NX_BOOLEAN

If true the dislocation_driving_force is considered, otherwise it is not.

line_energy: (required) NX_FLOAT {units=NX_ANY}

Prefactor :math:`0.5Gb^2` that factorizes the average ...

Prefactor \(0.5Gb^2\) that factorizes the average stored elastic energy per length dislocation line.

magnetic_field: (required) NXobject

In case of an applied magnetic field, a difference of the magnetic ...

In case of an applied magnetic field, a difference of the magnetic susceptibility can exert a driving force on the grain boundary such that the boundary migrates into the volume with the higher magnetic energy.

is_active: (required) NX_BOOLEAN

If true the magnetic_driving_force is considered, otherwise it is not.

triple_line_mobility: (required) NXobject

A triple line mediates the atomic arrangement differences between three ...

A triple line mediates the atomic arrangement differences between three interface patches. Therefore, the triple line is a defect that may not have the same mobility as adjoining grain boundaries and thus it may exert what can be conceptualized as a drag (resistance) to the motion of the adjoining interface patches.

drag: (required) NX_FLOAT {units=NX_ANY}

Assumed triple junction drag.

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/contributed_definitions/NXmicrostructure_gragles_config.nxdl.xml