About Layered Shells
A layered shell, also known as a composite laminate, is a thin-walled structure in 3D having many layers of different orthotropic (or optionally isotropic/anisotropic) material stacked on top of each other. A layered shell can be active either on free surfaces embedded in 3D or on the boundary of a solid object in 3D. In the latter case, it can be used to model a reinforcement on the surface of a solid object.
Figure 6-1: Geometry of a doubly curved laminated shell.
Figure 6-1 shows the uniform thickness doubly curved laminated shell having an orthogonal curvilinear coordinate system () and a total thickness (d).
A typical stacking sequence of a composite laminate having n layers is shown in Figure 6-2. The thickness of each layer (dk), as well as the fiber direction in each layer (θk) with respect to first principal direction (ξ1) of the laminate are indicated. A counterclockwise rotation of the fiber direction with respect to the (ζ) direction is considered as positive.
Figure 6-2: A typical stacking sequence of a composite laminate showing thickness and fiber orientation in each layer.
For a general description of this section, see About Laminated Composite Shells in the documentation for the Composite Materials Module.
In COMSOL Multiphysics, layered shells can be analyzed either by the layerwise theory using the Layered Shell interface, or by the first order shear deformation theory (ESL-FSDT) theory using the Linear Elastic Material, Layered material model in the Shell interface. The layerwise theory of modeling a layered shell is discussed in the next section.
The first order shear deformation theory (ESL-FSDT) of modeling a layered shell is described in Theory for FSDT Laminated Shell.