Material Models in Thin Layers
After selecting the approximation, Solid, Membrane, or Spring, the strain tensor in a geometrically linear analysis is computed from
and for a geometrically nonlinear analysis from
Then the material models are defined by the corresponding strain tensor.
There are some cases when a small strain formulation could be useful, even though the study step is geometrically nonlinear. One such case is contact analysis, where the study step is always geometrically nonlinear, but where a geometrically linear formulation is sufficient to describe the thin layer.
See the Linear Elastic Material, Nonlinear Elastic Materials, and Hyperelastic Materials sections for details.
For anisotropic data, the coefficients are given with respect to the boundary system. See the Boundary System section for details.
You can incorporate inelastic effects by adding the following subnodes to a Linear Elastic Material or Nonlinear Elastic Material node in thin layers:
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Thermal Expansion and Thermoelastic Damping
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Hygroscopic Swelling
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Initial Stress and Strain
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External Stress
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External Strain
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Inelastic Strain Rate
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Damping
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Linear Viscoelasticity
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Elastoplastic Materials
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Fibers for Linear and Nonlinear Elastic Materials
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Creep
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Viscoplasticity
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Damage Models (Linear Elastic Materials)
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Safety Factor Evaluation
The following subnodes are available for a Hyperelastic Material:
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Thermal Expansion and Thermoelastic Damping
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Hygroscopic Swelling
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External Stress
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External Strain
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Inelastic Strain Rate
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Damping
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Large Strain Viscoelasticity
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Elastoplastic Materials
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Creep and Viscoplasticity for Large Strains
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Polymer Viscoplasticity
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Fibers for Hyperelastic Materials
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Mullins Effect