Layered Linear Elastic Material
The Layered Linear Elastic Material node adds the equations for a layered linear elastic shell, or a laminated composite shell.
The material properties, orientations, 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.
For a general description about layered materials, see Layered Materials in the documentation for the Composite Materials Module.
By adding the following subnodes to the Layered Linear Elastic Material node you can incorporate many other effects:
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Thermal Expansion (for materials)
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Hygroscopic Swelling
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Initial Stress and Strain
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External Stress
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Damping
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Safety
The Layered Linear Elastic Material node is only available with the Composite Materials Module (see http://www.comsol.com/products/specifications/).
The Layered Linear Elastic Material node is only available in 3D and not in 2D axisymmetry.
Layer Selection
In the Layer drop-down, select a Layered Material Link or Layered Material Stack defined under Materials in the same component as the Shell interface.
At this node, it is not possible to select only few layers from a layered material as all the layers of a layered material are selected by default once a Layered Material Link or Layered Material Stack is chosen.
For a general description of this section, see Layer Selections in the documentation for the Composite Materials Module.
Boundary Selection
The boundary selection on this node is similar to the Linear Elastic Material node however only those boundaries are allowed to select which are part of the selection of a layered material defined in Layered Material Link or Layered Material Stack node.
Linear Elastic Material
Select a linear elastic Solid model—Isotropic, Orthotropic, or Anisotropic and enter the settings as described for the Linear Elastic Material for the Solid Mechanics interface. Note that:
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For Orthotropic no values for Ez, νyz, or νxz need to be entered due to the shell assumptions.
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For User defined Anisotropic a 6-by-6 symmetric matrix is displayed. Due to the shell assumptions, you only need to enter values for D11, D12, D22, D14, D24, D55, D66, and D56.
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The material orientation is always interpreted in a laminate coordinate system aligned with the shell boundary as described in Local Coordinate Systems together with the orientation of each layer specified on a layered material.
Geometric Nonlinearity
In this section there is one check box Force linear strains. If a study step is geometrically nonlinear, the default behavior is to use a large strain formulation in all domains. There are however some cases when you would still want to use a small strain formulation for a certain domain. In those cases, select the Force linear strains check box. When selected, a small strain formulation is always used, independently of the setting in the study step.
Shear Correction factor
In this section there is a drop-down input to define the value of shear correction factors. The two options available are Automatic and User defined. Once User defined option is selected, you can enter the values of k23 and k13.
To display this section, click the Show button () and select Advanced Physics Options.
Location in User Interface
Context Menus
 Shell>Material Models>Layered Linear Elastic Material
Ribbon
Physics tab with Shell selected:
Boundaries>Material Models>Layered Linear Elastic Material