Layered Material Stack
In the Layered Material Stack node (), 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 Layered Material node, you define four, and then add this definition five times in a Layered Material Stack.
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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 Layered Material nodes, and use a number of Layered Material Stack nodes to combine them into different configurations.
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Two Layered Material Stack nodes can have parts of their definitions linked to the same Layered Material node. When a transition through a continuity feature is used, the corresponding layers in two laminates defined as stacks can be connected automatically.
Ply modeling can be achieved from the selection of substack materials. By using different selections on each stack member, you can create ply-based selections. From the ply-based selections, a set of the product selections, called zone-based selections, can be deduced and displayed in a Stack Zone Definition section (see below).
The Layered Material Stack node is located in the Layers submenu under a Materials node. To compose the stack, you add subnodes to the Layered Material Stack. 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 Transform list, choose one of the following options:
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 None (the default), for no transformation.
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 Symmetric or Antisymmetric, 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 Mirror in list: Upside (the default) or Downside. 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 Merge middle layers check box to merge the two middle layers into one to create an odd symmetric layer.
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 Repeated, to create a number of repeating stacks, which you enter in the Number of repeats field (default: 1).
Select the Scale 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:
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 (sym) for the symmetric layers.
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 (asym) for the antisymmetric layers.
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 (repX) for the repeated layers (number X).
Click the Layer Cross Section Preview button ( to plot a preview of the layer cross section including the transformation. You can also click the downward pointing arrow to choose Layer Cross Section Preview () or Create Layer Cross Section Preview (), which adds the preview plot as a new plot group under Results. Click the Layer Stack Preview button () to get a preview of the stack with the transformation. Click the Create Layer Stack Plot button () to add the preview of the layer stack as a new plot group under Results.
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 Coordinate system defining the principal directions of the laminate. The orientation of each layer, given in the Layered Material node, is a rotation from the first coordinate axis of this coordinate system. Only Boundary System coordinate systems can be selected.
Choose a Position — Midplane on boundary, Down side on boundary, Up side on boundary, or User defined. This controls the possible offset of the layered material from the geometrical boundary on which the mesh exists (the reference surface). For User defined, enter a value for the Relative midplane offset. The value 1 corresponds to Down side on boundary, and the value −1 corresponds to Up side on boundary. Values may be outside the range −1 to 1, in which case the reference surface is outside the laminate. If you use ply modeling, these additional positions are available: Midplane of stack member on boundary, Downside of stack member on boundary, Upside of stack member on boundary. If you choose one of those positions, also choose a member of the ply stack from the Stack member list. Also, with one of those positions, the Automatic alignment when the selected stack member is not available check box is selected by default. The stack members (in zones that do not have the selected stack member) will then be aligned with the stack members in the zone that have the selected stack member. Clear it if you do not want that automatic alignment.
The Position setting is only used by physics features where the physical behavior depends of the actual location, such as structural shells.
By clicking the Layer Cross Section Preview () 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.
You can also click the downward pointing arrow to choose Layer Cross Section Preview () or Create Layer Cross Section Preview (), which adds the preview plot as a new plot group under Results.
Stack Zone Definition
This section is available if there are multiple zones. It then lists the names of the zones, the stack members for each zone, and the boundary selections for each zone.
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 Material list. The default settings is Same as layered material, 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 Go to Material () button, you can jump to the settings for the selected material.
Click the Add Material from Library 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 Material list.
Preview Plot Settings
In this section, you can fine-tune the display in the preview plot.
The value of the Thickness-to-width ratio controls the height in the y direction. The width is always unity.
Deselect the Shows labels in cross-section plot check box to remove the text labels showing layer names and materials.
Material Contents
See the documentation for Material Contents for the Material node.
The Value column will usually contain the string Layer, indicating that the actual value is layer dependent.
Appearance
See the documentation for Appearance for the Material node.