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.

Select the layer or layers for which this swelling strain contribution is to be added. The Layer selector inherits the value set in the parent Linear Elastic Material node. When it is set to All layered materials, you cannot access the individual layers.

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

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

Physics tab with Linear Elastic Material node selected in the model tree:
Attributes>Hygroscopic Swelling