6.12. Surface Coating

This feature enables you to apply a surface coating (shell layer) of a specified material and thickness over one or more faces of your model. This feature is beneficial when you want to include the ability to accurately evaluate surface stresses or to overlay your structure with thin parts, such as modelling Thermal Barrier Coatings or sheet metal over support structures. To accurately model this type of application, Mechanical enables you to specify the thickness, stiffness behavior, coordinate system, and material.

Note: Surface Coating is also a Scoping Method option for results.

Important: During a Cyclic Symmetry analysis, the application does not expand Surface Coating results.

Requirements

Note the following requirements for the Surface Coating feature:

It can only be applied to the surfaces (faces) of solid bodies (shells/sheets are not supported.).
Supported by 3D analyses only.
Is only supported for structural analysis types that are using the Mechanical APDL Solver. Analyses include Static Structural Analysis, Transient Structural Analysis, Transient Structural Analysis Using Linked Modal Analysis System, and Linear Dynamic Analysis types.
It uses SHELL181 and SHELL281.
The mesh of the bodies onto which you apply a Surface Coating should contain same Element Order (Linear or Quadratic).

Application

To create a Surface Coating:

You can either:
1. Select the Geometry object and click Surface Coating option from the Modify group on the Geometry Context tab.
  Or...
2. Right-click on the Geometry object or in the Geometry window and select Insert > Surface Coating.
  Or...
3. Select the desired faces available in the Geometry window, right-click, and select Insert > Surface Coating. This option automatically specifies the Geometry property in the Details view and therefore negates the next step.
Specify the Scoping Method property as either Geometry Selection or Named Selection. Based on the selection made in this step, select a:
- Geometry (faces only) and click Apply in the Details view for the Geometry property.
  or...
- Face-based user-defined named selection from the drop-down list of the Named Selection property.
Specify the Stiffness Behavior as either Stress Evaluation Only (default), Membrane Only, or Membrane and Bending. If you set this property to Stress Evaluation Only, no Thickness entry is necessary.
Note: By default, Mechanical automatically sets the Shell Offset to Bottom for all Stiffness Behavior settings.
Select a material for the surface coating from the fly-out menu of the Material property.
Specify a Thickness for the surface body.
As needed, change the Coordinate System setting. The Default Coordinate System option is based on the geometry scoping specified above.

See the Surface Coating object reference page for additional information about the properties of this feature.