The Hyperelastic Material, Layered node adds the equations for a layered hyperelasticity at large strains. Hyperelastic materials can be suitable for modeling rubber and other polymers, biological tissue, and also for applications in acoustoelasticity.

The Nonlinear Structural Materials Module is required for this feature. For details, see https://www.comsol.com/products/specifications/.

If the Composite Materials Module is available, this material model can be applied to arbitrary layers in a multilayered shell. The material properties and layer thicknesses are defined using Layered Material node. The offset, and local coordinate system, in which material orientations and results are interpreted, is defined by Layered Material Link or Layered Material Stack node.

When a hyperelastic material is included in your model, all studies are geometrically nonlinear. The Include geometric nonlinearity checkbox in the study settings is selected and cannot be cleared.

By adding the following subnodes to the Hyperelastic Material, Layered node you can incorporate many other effects.

Without the Composite Materials Module, only single layer hyperelastic shells can be modeled. This is still useful. In particular, it is used for nonlinear material models, but also for some multiphysics couplings. For single layer materials, an ordinary Material node can be used, as long you include a Shell property group in which, for example, the thickness is given.

For this node, the Shell Properties section is only used for selecting a material model, but not individual layers.

Data given in the other sections of this node applies to all layers. Thus, if you enter material data explicitly, rather relying on the default From material option, you will override that material property for all selected layers.

The boundary selection in this node is similar to the Linear Elastic Material node. It is however only possible to select boundaries that are part of the selection of a layered material defined in a Single Layer Material, Layered Material Link, or Layered Material Stack node.

Select a Material model and enter the settings as described for the Hyperelastic Material for the Solid Mechanics interface.

Enter the shear correction factors for transverse shear k23 and k13.

Physics tab with Shell selected: