*CRADIATE

Specify radiation conditions and associated sink temperatures at one or more nodes or vertices.

This option is used to apply radiation boundary conditions between a node and a nonreflecting environment in fully coupled thermal-stress analysis. In Abaqus/Standard it is also used for all procedures that solve for nodal temperature degrees of freedom.

This page discusses:

See Also
In Other Guides
Thermal Loads

Products Abaqus/Standard Abaqus/Explicit Abaqus/CAE

Type History data

LevelStep

Abaqus/CAE Interaction module

Optional parameters

AMBIENT AMPLITUDE

Set this parameter equal to the name of the AMPLITUDE option that gives the variation of the ambient temperature with time.

If this parameter is omitted in an Abaqus/Standard analysis, the reference magnitude is applied immediately at the beginning of the step or linearly over the step, depending on the value assigned to the AMPLITUDE parameter on the STEP option (see Defining an Analysis). If this parameter is omitted in an Abaqus/Explicit analysis, the reference magnitude is applied immediately at the beginning of the step.

OP

Set OP=MOD (default) for existing CRADIATE definitions to remain, with this option modifying existing radiation conditions or defining additional radiation conditions.

Set OP=NEW if all existing CRADIATE definitions applied to the model should be removed.

PHANTOM

This parameter applies only to Abaqus/Standard analyses.

Set PHANTOM=NODE to specify radiation conditions and associated sink temperatures at a phantom node that is originally located coincident with the specified real node in an enriched element.

Set PHANTOM=EDGE to specify radiation conditions and associated sink temperatures at a phantom node located on an element edge between the two specified real corner nodes in an enriched element. This setting applies only to nodes with both pore pressure and temperature degrees of freedom.

RADIATION AMPLITUDE

Set this parameter equal to the name of the AMPLITUDE option that gives the variation of the total radiation flux with time.

If this parameter is omitted in an Abaqus/Standard analysis, the total radiation flux, accounting for any AMBIENT AMPLITUDE, is applied immediately, independent of the value assigned to the AMPLITUDE parameter on the STEP option. If this parameter is omitted in an Abaqus/Explicit analysis, the total radiation flux, accounting for any AMBIENT AMPLITUDE, is applied immediately at the beginning of the step.

REGION TYPE

This parameter applies only to Abaqus/Explicit analyses.

This parameter is relevant only for concentrated radiation conditions applied on the boundary of an adaptive mesh domain. If concentrated radiation conditions are applied to nodes in the interior of an adaptive mesh domain, these nodes will always follow the material.

Set REGION TYPE=LAGRANGIAN (default) to apply a concentrated radiation condition to a node that follows the material (nonadaptive).

Set REGION TYPE=SLIDING to apply a concentrated radiation condition to a node that can slide over the material. Mesh constraints are typically applied to the node to fix it spatially.

Set REGION TYPE=EULERIAN to apply a concentrated radiation condition to a node that can move independently of the material. This option is used only for boundary regions where the material can flow into or out of the adaptive mesh domain. Mesh constraints must be used normal to an Eulerian boundary region to allow material to flow through the region. If no mesh constraints are applied, an Eulerian boundary region will behave in the same way as a sliding boundary region.

Data lines to define radiation conditions

First line

  1. Node number or node set name.

  2. Appropriate area associated with the node where the concentrated radiation condition is applied. The default is 1.0.

  3. Reference ambient temperature value, θ 0 . (Units of θ .)

  4. Emissivity, ϵ .

Repeat this data line as often as necessary to define radiation conditions.

Data lines to define radiation conditions when PHANTOM=NODE

First line

  1. Node number of a real node that is originally located coincident with the phantom node.

  2. Appropriate area associated with the node where the concentrated radiation condition is applied. The default is 1.0.

  3. Reference ambient temperature value, θ 0 . (Units of θ .)

  4. Emissivity, ϵ .

Repeat this data line as often as necessary to define radiation conditions.

Data lines to define radiation conditions when PHANTOM=EDGE

First line

  1. Node number of one of the two real corner nodes to define an edge in an enriched element.

  2. Node number of the other real corner node to define an edge in an enriched element.

  3. Appropriate area associated with the node where the concentrated radiation condition is applied. The default is 1.0.

  4. Reference ambient temperature value, θ 0 . (Units of θ .)

  5. Emissivity, ϵ .

Repeat this data line as often as necessary to define radiation conditions.