External Stress
You can add the External Stress subnode to the Linear Elastic Material or Hyperelastic Material in order to specify an additional stress contribution which is not part of the constitutive relation. The external stress can be added to the total stress tensor, act as an extra load contribution, or behave as a residual stress.
In many cases External Stress and Initial Stress and Strain are interchangeable when prescribing stresses. In Initial Stress and Strain, the given stress is however always added to the stress tensor, whereas the option to use the stress as only a load contribution exists only in External Stress.
Shell Properties
Select the layer or layers for which this stress contribution is to be added.
Table 6-17: Layer Selections; External Stress.
Selection
Use All Layers
Selection of Individual Layers
Boundary
Same as parent selection when the node is added.
When Use all layers is not selected.
Only a subset of the layers selected in the parent can be selected.
Coordinate System Selection
The Coordinate system list contains all applicable coordinate systems in the model, including the Boundary system and the Layer local system. The Global coordinate system is selected by default. External stresses are specified along the axes of the selected coordinate system.
If the external stress input type differs between layers, you will need to add several External Stress nodes with different layer selections.
If the same layer is selected in two External Stress nodes being active on the same boundary, the contributions will be added.
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See Defining a Layer Local System in the Composite Materials Modeling chapter.
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All other settings are described in the documentation for External Stress in the Solid Mechanics interface.
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For a general description of layer and interface selections, see The Shell Properties and Interface Selection Sections.
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You can describe stress values with a through-thickness variation by explicitly or implicitly using expressions containing the extra dimension coordinate as described in Using the Extra Dimension Coordinates.
Location in User Interface
Context Menus
Layered Shell > Linear Elastic Material > External Stress
Layered Shell > Hyperelastic Material > External Stress
Ribbon
Physics tab with Linear Elastic Material or Hyperelastic Material node selected in the model builder tree:
Attributes > External Stress