When temperatures are transferred to a structural, electric, or LS-DYNA analysis, an Imported Body Temperature object is automatically inserted to represent the transfer.
If the load is applied to one or more surface bodies, the Shell Face option in the Details pane enables you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. By default, the temperatures are applied to both the top and bottom faces of the selection. For applicable transfers or for specific steps to transfer data, see the Imported Boundary Conditions section.
Be sure to review the following information about the requirements and considerations when employing this loading condition.
Operational Rules for Imported Thermal Loads
Observe the following operational conditions when you apply Imported Body Temperature loads and Thermal Condition on the same geometry. For each load step:
An active or reactivated Imported Body Temperature load overwrites any Thermal Condition loads on common geometry selections.
The most recently added Imported Body Temperature load, whether active or reactivated overwrites any other Imported Body Temperature loads that exist in the tree and that share common geometry or node selections.
Imported Body Temperature loads for which no commands are sent to the solver, for a particular load step, are overwritten by a reactivated or deactivated:
Thermal Condition load on common geometry selections.
Imported Body Temperature load on common geometry selections.
The Imported Body Temperature will remain deleted until it gets reactivated during one of the subsequent steps (status change from deactivated to active).
For additional rules about when multiple load objects of the same type exist on common geometry selections, see the Activating and Deactivating Loads Help.
Note: For an active, reactivated, or deactivated loading condition, the application sends a command to the solver. The Tabular Loading topic below describes when during the solution process the command is sent to the solver.
Tabular Loading Processing Specifications
- Processing Characteristics
Note the following tabular loading characteristics for Imported Body Temperature loads:
When Imported Body Temperature loads are not sent using tables, the commands are sent to the solver at load steps specified in the Data View worksheet or when the load is reactivated or deactivated.
For Imported Body Temperature loads specified in Tabular Data, commands are sent to the solver only at the first active or reactivated load step.
- Defining the Program Controlled Option
The Tabular Loading property has the following options:
: The application selects either or . The selection depends upon whether the Analysis Time (s) values in the Data View pane match the End Time values of the Tabular Data window. If the value match, the application selects the option. If they do not match, then the option is used.
: Temperature values are Ramped based on the Analysis Time (s) table.
: Temperature values are Stepped based on the Analysis Time (s) table.
: Temperature values are applied as a constant at the end of each load step and ramped during the load step.
Tip: The application processes the and options the same except that when using the option, Analysis Time values must match the End Times exactly. Otherwise, the application generates an error message. The option is not affected buy this limitation.
- Specifying Source Time
The Source Time property includes the following options:
: All time points from the upstream Thermal analysis populate the Source Time (s) column in the Data View pane. And, by default, the Analysis Time (s) column contains the same values. When selected, a Graphics Controls category displays in the Details pane enabling you to specify the display of the load data by Active Row or Time.
: This option filters the data points from the upstream Thermal analysis based on the minimum and maximum input values and populates the Source Time (s) column accordingly. When selected, the additional properties, Minimum and Maximum display. These properties enables you to enter minimum and maximum time values for which to display results. When you enter minimum and maximum time values, a Graphics Controls category displays in the Details pane enabling you to specify the display of the load data by or .
(default): Manually enter desired data points to obtain load data from the upstream Thermal analysis in order to connect them to Analysis Time of the downstream Structural analysis.
Based on the option that you select for the Source Time property, the Tabular Loading property is set depending upon on whether the values of Analysis Time column match the values of the Load Step End Times values of the Structural analysis.
General Notes
Review to the following to make sure that you properly configure your imported load.
If you have a Nonlinear Adaptive Region object present in a Static Structural analysis, the Imported Body Temperature includes the property: Apply To Initial Mesh. You use this property to specify whether the boundary conditions are applied directly to the initial mesh or to the newly generated mesh.
Adaptive Convergence objects inserted under an environment that is referenced by an Imported Body Temperature object will invalidate the Imported Body Temperature object, and not allow a solution to progress.
For a particular load step, an active Imported Body Temperature load will overwrite any Thermal Condition loads on common geometry selections.
When a Thermal Condition is specified on the Top or Bottom shell face of a surface body, the opposite face defaults to the environment temperature unless it is otherwise specified from another load object.
For an assembly of bodies with different topologies, you must define a separate Imported Body Temperature load for surface bodies.
The values used in the solution are calculated by first converting the imported load values into the solver unit system and then multiplying the scale value.
For each load step, if an Imported Body Temperature load and a Thermal Condition load are applied on common geometry or node selections, the Imported Body Temperature load takes precedence. An active Imported Body Temperature load will also overwrite other Imported Body Temperature loads that exist higher (previously added) in the tree, on common geometry or node selections. For additional rules when multiple load objects of the same type exist on common geometry selections, see Activating and Deactivating Loads.
If a scale factor is specified, the values used in the solution are calculated by first converting the imported load values into the solver unit system and then multiplying the scale value.
For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. For additional information, see External Data.
For an LS-DYNA analysis, Mechanical-Based Mapping and Source Time are not available.
Load Vector Controls for Substructure Generation Analyses
You can insert Imported Body Temperature objects into a Substructure Generation analysis when Beta Options are active. The Details pane will display the Load Vector Controls category. This category includes the following properties.
Load Vector Assignment: Options include (default) and . If you select , a Load Vector Number property displays, as described below, enabling you to define the value.
Load Vector Number (Real): Use this property to manually specify a Load Vector Number (Real) value. This value can be any number greater than 1 – the application reserves this value for pre-stressed Substructure Generation analyses. If multiple loads have the same load vector number, the application groups these loads during the solution process to generate a single load vector that is the combined effect of all grouped loads.