Defining a Layered Material

Start by adding a at the node under . Then, take the following steps to define the laminate:

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Add the required number of layers in the section of a node.

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Define the referenced materials under the node. You can either add a and fill in the required material properties or choose a material from the .

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Select the appropriate material in each layer.

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Define the rotation angle (in degrees) for each layer. This is the orientation of the fiber direction with respect to the principal laminate coordinate system.

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Define the thickness of each layer.

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By default, two mesh elements in each layer are used which means there are two sublayers in each material layer. Optionally, you may want to either increase or decrease the number of mesh elements in an individual layer in order to improve the accuracy or reduce the computation time.

Note that required material properties for the material in a certain layer depends on the chosen in the node in Layered Shell or node in Shell interface.

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For the model (with Young’s modulus and Poisson’s ratio option), scalar values of Young’s modulus and Poisson’s ratio are required.

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For the and model, Young’s modulus, shear modulus, and Poisson’s ratio along the principal material directions is required.

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For the model, the full homogenized elasticity matrix of along the principal material directions is required.

Interface Materials

By default, no material is selected on the interface between two layers in the through-thickness direction. The material properties at the interface are taken as an average of the two adjacent layer properties.

All the layers are assumed in a continuity state. Optionally, in order to model a very thin layer of material, for example a glue layer between the two material layers, a material can be added in section. If an interface material is defined, you can create a discontinuity between two layers and use the interface material properties. To do this, add a or node in the Layered Shell interface. All interfaces selected in that node should have a material assignment, but there is no need to assign a material to interfaces which are not affected by such special features.

Preview Plots

As the physical geometry is only the boundaries, it becomes important to visualize the layup, including stacking sequence and thickness values for each layer.

You can do that by creating (

) and (

) plots. An example of a layer cross section plot showing a 2D cross section of a laminate having is shown in Figure 3-7. The thickness of each layer is visible. An example of a layer stack preview plot showing the stacking sequence is shown in Figure 3-8.

Figure 3-7: Example of a layer cross section preview plot showing a composite laminate having 5 layers with different thickness values.

Figure 3-8: Example of a layer stack preview plot showing a composite laminate having 5 layers with stacking sequence [0/45/90/-45/0].

Note that in the layer stack preview plot, the distance between any two layers is always the same and it does not reflect the actual thickness of the layers.

Since the preview plots are used for a variety of composite laminates having different combination of number of layers, thickness values, and stacking sequence, it is possible to customize the plot settings in terms of changing the thickness to width ratio or the distance between the orientation lines. It is also possible to switch off the orientation lines and labels.

You can also create the two preview plots under section using and buttons respectively. This helps in storing the preview plots in the model and also allows them to be available in an application, built on top of the model.

In the COMSOL Multiphysics Reference Manual:

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Layered Material