Layered Material Stack

), you can compose a new layered material by stacking other layered materials (including Material nodes that define single-layer materials) on top of each other. There are three main reasons why you may want to do this:

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The layup is repetitive, say with the same four layers repeated five times. Rather than defining twenty layers in a node, you define four, and then add this definition five times in a .

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There are layer drop-offs, that is some layers are not present everywhere in the structure. Then, it is efficient to create only subsets of the laminate in nodes, and use a number of nodes to combine them into different configurations.

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Two nodes can have parts of their definitions linked to the same node. When a transition through a continuity feature is used, the corresponding layers in two laminates defined as stacks can be connected automatically.

The node is located in the Layers submenu under a Materials node. To compose the stack, you add subnodes to the . These subnodes can be either a Layered Material or a Layered Material Link (Subnode). You can add any number of subnodes, and mix the two types. The order of the subnodes determines the ordering of the layers in the final laminate.


	The interface between the two Layered Material Stack nodes takes the interface material from the first Layered Material Stack node and ignores the interface material of the second Layered Material Stack node.

Layered Material Settings

From the list, choose one of the following options:

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(the default), for no transformation.

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or , to create a symmetric or antisymmetric layered material when the information of layers of one side of the midplane is supplied. Choose which side to mirror in from the list: (the default) or . Upside means that the symmetry layers are on the top of the original layers. The symmetry line is the top-side boundary. Downside means that the symmetry layers are on the bottom of the original layers. The symmetry line is the bottom-side boundary. Select the check box to merge the two middle layers into one to create an odd symmetric layer.

•

, to create a number of repeating stacks, which you enter in the field (default: 1).

Select the check box to scale the layered material’s thickness with a factor (default: 1). If you have defined a layer with a scaling factor, it appears in the preview window with a darker color than a nonscaled layer.


	The preview is not shown in the base geometry space, so it will not show any geometrical dependency.

The labels of the newly created layers include a suffix to distinguish them from the original layers:

•

for the symmetric layers.

•

for the antisymmetric layers.

•

for the repeated layers (number X).

Click the button (

to plot a preview of the layer cross section including the transformation. Click the button (

) to get a preview of the stack with the transformation.


	A combination of transformations can be made by defining the transformations for both the Layered Material Stack node and a Layered Material Link subnode.

Orientation and Position

Select a defining the principal directions of the laminate. The orientation of each layer, given in the node, is a rotation from the first coordinate axis of this coordinate system. Only coordinate systems can be selected.

Choose a — , , , or . This controls the possible offset of the layered material from the geometrical boundary on which the mesh exists (the reference surface). For , enter a value for the . The value 1 corresponds to , and the value −1 corresponds to . Values may be outside the range −1 to 1, in which case the reference surface is outside the laminate.

The setting is only used by physics features where the physical behavior depends of the actual location, such as structural shells.

By clicking the (

) button, you get a preview plot of the stacked layered material, including the location of the reference surface. In Figure 9-13, a laminate composed of three stacked layered materials, each consisting of three layers is shown. Note that there is a slight indentation, used for emphasizing the transition from one part of the stack to the next.

Figure 9-13: Layer cross section preview plot with relative offset set to Down side on boundary.

Nonlayered Material Settings

In some cases, a single standard material definition is needed on the same boundary as a layered material. This can for example be the case if two different physics interfaces are active on the same boundary, but only one of them supports a layered material definition. You can select any nonlayered material from the list. The default settings is , which means that the nonlayered material properties are computed as an average value of the layer’s material properties. This selection is completely analogous to using a Material Link.


	You cannot use an ordinary Material or Material Link with the same selection as the Layered Material Stack. These nodes override each other.

By clicking the (

) button, you can jump to the settings for the selected material.

Click the button (

) to add a global material from the material libraries or a new blank global material. The added material then becomes the one selected in the list.

Preview Plot Settings

In this section, you can fine-tune the display in the preview plot.

The value of the controls the height in the y direction. The width is always unity.

Deselect the check box to remove the text labels showing layer names and materials.

Material Contents

See the documentation for Material Contents for the node.

The column will usually contain the string Layer, indicating that the actual value is layer dependent.

Appearance

See the documentation for Appearance for the node.