Layered Linear Elastic Material

The node adds the equations for a layered linear elastic shell.

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

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

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For a general description about layered materials, see Layered Materials in the documentation for the Composite Materials Module.

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By adding the following subnodes to the 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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Some of these material models are only available together with the Nonlinear Structural Materials Module (see http://www.comsol.com/products/specifications/).


	The Layered Linear Elastic Material is only available for the Shell interface, but not for the Plate interface.

Shell Properties

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

Table 5-2: Layer Selections; Linear Elastic Material
Selection	Use All Layers	Selection of Individual Layers
Boundary	Default when added	No


	For a general description of this section, see Layer and Interface Selections in the documentation for the Composite Materials Module.

Boundary Selection

The boundary selection in this node is similar to the node. It is however only possible to select boundaries which are part of the selection of a layered material defined in or node.

Linear Elastic Material

Select a linear elastic — , , or and enter the settings as described for the Linear Elastic Material for the Solid Mechanics interface. If the layers have different types of anisotropy properties, select the one that is most complex.

Note that:

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For no values for Ez, νyz, or νxz need to be entered due to the shell assumptions.

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For 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.

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 and . Once option is selected, you can enter the values of k23 and k13.

To display this section, click the button (

) and select in the dialog box.

Geometric Nonlinearity

In this section there is one check box . 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 check box. When selected, a small strain formulation is always used, independently of the setting in the study step.

Energy Dissipation

The section is available when you also have the Nonlinear Structural Materials Module. Then, to display this section, click the button (

) and select in the dialog box.

Location in User Interface

Context Menus

Ribbon

Physics tab with selected: