*EXTERNAL FIELD

Import external fields to define distributions, initial conditions, and history-dependent fields or to perform a submodel analysis.

This option is used to import external fields. It can be used in conjunction with the DISTRIBUTION option to define a spatial distribution, with the INITIAL CONDITIONS option to prescribe initial conditions, or with the FIELD IMPORT option to define history-dependent fields (such as loads, boundary conditions, and predefined fields) or to perform a node-based submodel analysis.

This page discusses:

See Also
*DISTRIBUTION
*INITIAL CONDITIONS
*FIELD MAPPER CONTROLS
*FIELD OPERATIONS
In Other Guides
General Capability for Importing External Fields
Distribution Definition
Initial Conditions
Output Variables

Products Abaqus/Standard Abaqus/Explicit

Type Model or history data

LevelPartPart instanceAssemblyModel

Using an external field to define distributions and initial conditions

Required parameters

FILE
Set this parameter equal to the name of the SIM database (.sim) file from which results data are to be read.

Optional parameters

INC

Set this parameter equal to the increment from which to import field values.

The INC parameter and the TIME parameter are mutually exclusive. This parameter is ignored if the MODE parameter is specified.

If this parameter is omitted and neither the MODE parameter or the TIME parameter is specified, the field values are read from the last increment of the specified step or from the last step if the STEP parameter is omitted.

MODE

Set this parameter equal to the mode number from which to import field values.

The MODE parameter and the TIME parameter are mutually exclusive. If the STEP parameter is omitted, the last step from the previous analysis is used.

STEP

Set this parameter equal to the step from which to import field values.

The STEP parameter and the TIME parameter are mutually exclusive.

If this parameter is omitted and the TIME parameter is not specified, the field values are read from the last step.

TIME

Set this parameter equal to the time at which to import field values. Linear interpolation is performed using two saved time points of the previous analysis to obtain the field values at the specified time. The time is specified as the total time.

The TIME parameter and the INC and STEP parameters are mutually exclusive.

If the TIME, STEP, and INC parameters are omitted, the last stored frame is imported.

Data lines to use an external field to define distributions and initial conditions

First line

  1. Name space of the region in the model used in the current analysis. Use NODES to indicate that the region is a node set; use ELEMENTS to indicate that the region is an element set. If omitted, the default is ELEMENTS.

  2. Name of the region (node set or element set) defined in the current model where imported fields are specified. If omitted, imported fields are specified on the entire model in the current analysis.

    The region can be either a node set or an element set regardless of the location where imported fields are specified. When a nodal field is specified on an element set, the field data are specified on all nodes of the elements in the specified element set. When an element field is specified on a node set, the field data are specified on all elements containing the nodes in the node set; elements connected to nodes that are not in the node set are not included.

  3. Identifying key for the field imported when EXTERNAL FIELD is used with the following initial conditions:

    • INITIAL CONDITIONS, TYPE=DAMAGE INITIATION, CRITERION=MSFLD; use MSFLDCRT as the identifying key for the Müschenborn and Sonne forming limit diagram–based damage initiation criterion and use ERPRATIO as the identifying key for the ratio of the principal strain rates.
    • INITIAL CONDITIONS, TYPE=ESDV; use ESDVn as the identifying key for the nth element solution-dependent variable.
    • INITIAL CONDITIONS, TYPE=HARDENING with the NUMBER BACKSTRESSES parameter specified; use PEEQ as the identifying key for the equivalent plastic strain, and use ALPHAn as the identifying key for the nth initial backstress.
    • INITIAL CONDITIONS, TYPE=SOLUTION; use SDVn as the identifying key for the nth solution-dependent state variable.
    Otherwise, not used.

  4. Name space of the region in the model used in the previous analysis. Use NODES to indicate that the region is a node set; use ELEMENTS to indicate that the region is an element set. If omitted, the default is ELEMENTS.

  5. Name of the region (node set or element set) defined in the previous model from which results data are to be imported. If omitted, results data are imported from the entire model in the previous analysis.

    The region can be either a node set or an element set regardless of the location of the results data to be imported. When a node-based field is imported and an element set is specified, the node-based field is extracted from nodes of the elements in the specified element set. When an element-based field is imported and a node set is specified, the element field is extracted from elements containing the nodes in the node set; elements connected to nodes that are not in the node set are not included.

  6. Output variable Identifying keys for the results field data imported from the referenced output database (.sim) file. For information on individual output variable identifiers, see Output Variables. In addition, you can specify variables that can be read from the output database (.sim) file but for which you cannot request output. For example, you cannot request output for the variable ORIENT, but it is found in the output database (.sim) file if an orientation field is associated with any of the other results fields.

  7. Specify the name of a mapping controls definition. If omitted, default mapping controls are used.

  8. Specify the name of a field operations definition.

Repeat this data line as often as necessary to define imported data for element sets or node sets.

Using an external field to define history-dependent fields

Required parameters

FILE
Set this parameter equal to the name of the output database file from which to read results data. For non-SIM databases, you must specify the reader executable name.

Optional parameters

AMPLITUDE

This parameter is meaningful only when importing fields at a specified snap-shot point.

Set AMPLITUDE=RAMP (default) to ramp the incoming fields over the analysis step.

Set AMPLITUDE=STEP to apply the fields at the beginning of the analysis step.

FREQ

This parameter is meaningful only when importing fields at a specified snap-shot point from a frequency-domain analysis. Frequency-domain analysis is supported only for non-SIM databases.

Set this parameter equal to the frequency defining the snap-shot point to import fields. Linear interpolation is performed between two saved frequency points of the upstream analysis to obtain the field values at the specified frequency.

MODE

This parameter is meaningful only when importing fields at a specified snap-shot point from a frequency-domain analysis. Frequency-domain analysis is supported only for non-SIM databases.

Set this parameter equal to the mode number defining the mode to import fields.

READER

This parameter is required when reading results from a supported solver database other than a SIM-database.

Set this parameter equal to the reader executable name. Consult the respective solver user’s guide for the reader executable name.

START TIME

This parameter is meaningful only when importing fields over a time range from a time-domain analysis.

Set this parameter equal to the start time to import fields. Field values are interpolated linearly between two saved time points in the upstream analysis results file to obtain the field values at the specified start time.

The time is specified as the step time when the STEP parameter is used; otherwise, total time is assumed.

If the START TIME and the END TIME parameters are omitted, field values are imported over the entire analysis step when the STEP parameter is used. Otherwise, values are imported over the entire analysis.

STEP

Set this parameter equal to the analysis step from which to import field values when reading from the SIM-database file.

If this parameter is specified, the TIME parameter to specify a snap-shot point and the START TIME and END TIME parameters to specify a time range refer to step time. Otherwise, total time is used.

END TIME

This parameter is meaningful only when importing field values over a time range from a time-domain analysis.

Set this parameter equal to the end time to import fields over a specified time range. Field values are linearly interpolated between two saved time points in the upstream analysis results file to obtain the field values at the specified end time.

The time is specified as the step time when the STEP parameter is used; otherwise, total time is assumed.

You must explicitly specify the end time value when the upstream and downstream analyses use different time scales and TIME SCALING=ON is specified.

If the START TIME and the END TIME parameters are omitted, field values are imported over the entire analysis step when the STEP parameter is used. Otherwise, values are imported over the entire analysis.

If the END TIME parameter is omitted, the end time is taken as the last saved fields of the upstream analysis step when the STEP parameter is used. Otherwise, the end time is taken as the last saved fields of the upstream analysis.

TIME

This parameter is meaningful only when importing field values at a snap-shot point from a time-domain analysis.

Set this parameter equal to the time at which to import field values. Field values are interpolated linearly between two saved time points of the upstream analysis to obtain field values at a specified time.

The time is specified as the step time when the STEP parameter is used; otherwise, total time is assumed.

If the TIME, MODE, and FREQ parameters are omitted, the last saved fields of the analysis step are used when the STEP parameter is specified. Otherwise, the last saved values at the end of the analysis are used.

TIME SCALING

This parameter is meaningful only when importing fields over a time range.

Set TIME SCALING=OFF (default) to use the same time scales between the upstream and downstream analyses.

Set TIME SCALING=ON to automatically scale time such that the time range of the upstream results are mapped over the downstream analysis step. You must specify an end time value explicitly in this case.

TYPE

Set TYPE=TIME RANGE (default) to import field data over a time range.

Set TYPE=SNAP SHOT to import fields at a snap-shot point (time, frequency, or mode number).

Data lines to use an external field to define history-dependent fields

First line

  1. Name space of the region in the model used in the current analysis. Use NODES to indicate that the region is a node set; use ELEMENTS to indicate that the region is an element set; or use SURFACE to indicate that the region is a surface. The default is ELEMENTS.

  2. Name of the region (node set, element set, or surface) defined in the current model where imported fields are specified.

  3. Identifying key for the field imported. The keys are defined in Identifying the Target and Source Fields.

  4. Name space of the region in the model used in the previous analysis. Use NODES to indicate that the region is a node set; use ELEMENTS to indicate that the region is an element set; use SURFACE to indicate that the region is a surface; or use MONITOR to read a monitor from a CST Studio analysis. The default is ELEMENTS.

  5. Name of the region (node set, element set, or surface) defined in the previous model from which results data are to be imported. If the region is a surface, you must specify a surface name. For node sets and element sets, the default is to import results data from the entire model in the previous analysis.

    The region can be either a node set, an element set, or a surface regardless of the location where imported fields are specified. When you import a node-based field and specify an element set or surface, the node-based field is extracted from the nodes of the elements in the specified element set or facets belonging to the specified surface. When an element-based field is imported and you specify a node set, the element field is extracted from elements containing the nodes in the node set; elements connected to nodes that are not in the node set are not included.

  6. Identifying keys for the results field data imported from the referenced output database (.sim) file. The keys are defined in Abaqus/Standard Output Variable Identifiers and Abaqus/Explicit Output Variable Identifiers.

  7. Specify the name of a mapping controls definition. If omitted, default mapping controls are used.

  8. Specify the name of an optional field operations definition.

Repeat this data line as often as necessary to import external fields.

Using an external field in a node-based submodel analysis

Required parameters

FILE
Set this parameter equal to the name of the output database (.sim) file for the global analysis.

Optional parameters

AMPLITUDE

This parameter is meaningful only when importing fields at a specified snap-shot point.

Set AMPLITUDE=RAMP (default) to ramp the incoming fields over the analysis step.

Set AMPLITUDE=STEP to apply the fields at the beginning of the analysis step.

START TIME

This parameter is meaningful only when importing fields over a time range.

Set this parameter equal to the start time to import fields. Field values are interpolated linearly between two saved time points in the global analysis results file to obtain the field values at the specified start time.

The time is specified as the step time when the STEP parameter is used; otherwise, total time is assumed.

If the START TIME and the END TIME parameters are omitted, field values are imported over the entire analysis step when the STEP parameter is used. Otherwise, values are imported over the entire analysis.

STEP

Set this parameter equal to the analysis step to import fields from the global model .

If this parameter is specified, the TIME parameter to specify a snap-shot point and the START TIME and END TIME parameters to specify a time range refer to step time. Otherwise, total time is used.

END TIME

This parameter is meaningful only when importing field values over a time range.

Set this parameter equal to the end time to import fields over a specified time range. Field values are interpolated linearly between two saved time points in the global analysis results file to obtain the field values at the specified end time.

The time is specified as the step time when the STEP parameter is used; otherwise, total time is assumed.

You must explicitly specify the end time value when the global and submodel analyses use different time scales and TIME SCALING=ON is specified.

If the START TIME and the END TIME parameters are omitted, field values are imported over the entire analysis step when the STEP parameter is used. Otherwise, values are imported over the entire analysis.

If the END TIME parameter is omitted, the end time is taken as the last saved fields of the global analysis step when the STEP parameter is used. Otherwise, the end time is taken as the last saved fields of the global analysis.

TIME SCALING

This parameter is meaningful only when importing fields over a time range.

Set TIME SCALING=OFF (default) to use the same time scales between the local and global analyses.

Set TIME SCALING=ON to automatically scale the time such that the time range of the global anaysis is mapped over the local analysis step. You must specify an end time value explicitly in this case.

TIME

This parameter is meaningful only when importing field values at a snap-shot point.

Set this parameter equal to the time at which to import field values. Field values are interpolated linearly between two saved time points of the global analysis to obtain field values at specified time.

The time is specified as the step time when the STEP parameter is used; otherwise, total time is assumed.

If the TIMEis omitted, the last saved fields of the analysis step are used when the STEP parameter is specified. Otherwise, the last saved values at the end of the analysis are used.

TYPE

Set TYPE=TIME RANGE (default) to import field data over a time range.

Set TYPE=SNAP SHOT to import fields at a snap-shot point (time, frequency, or mode number).

Data lines to use an external field in a node-based submodel analysis

First line

  1. Use NODES (default) to indicate that the region is a node set.

  2. Name of the region (node set) defining the driving nodes of the submodel.

  3. Identifying key for the field imported. The keys are defined in Identifying the Target and Source Fields.

  4. Use ELEMENTS (default) to indicate that the region is an element set.

  5. Name of the region (element set ) defined in the previous model from which results data are to be imported. By default, results data are imported from the entire model in the previous analysis.

  6. Identifying keys for the results field data imported from the referenced output database (.sim) file. The keys are defined in Abaqus/Standard Output Variable Identifiers and Abaqus/Explicit Output Variable Identifiers.

  7. Specify the name of a mapping controls definition. By default, default mapping controls are used.

  8. Specify the name of an optional field operations definition.

Repeat this data line as often as necessary to import external fields.