Hygroscopic Swelling

Hygroscopic swelling is an internal strain caused by changes in moisture content. This strain can be written as

where βh is the coefficient of hygroscopic swelling, Μm is the molar mass, cmo is the moisture concentration, and cmo,ref is the strain-free reference concentration.

You can provide a concentration with a through-thickness variation by explicitly or implicitly use expressions containing the extra dimension coordinate as described in Using the Extra Dimension Coordinates.

Shell Properties

Select the layer or layers for which this swelling strain contribution is to be added.

Table 6-11: Layer Selections; Hygroscopic Swelling
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.

If the swelling properties differ between layers, you will need to add several nodes with different layer selections. If only the material data values differ, you can use a single node with . The data for each layer is then received from global nodes.

If the same layer is selected in two nodes being active on the same boundary, the second definition will override the previous.

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All other settings for the node are described in the documentation for Hygroscopic Swelling 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 provide parameters for the swelling 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

Ribbon

Physics tab with or node selected in the model tree: