What is a surface?

Surfaces are collections of faces and edges or collections of element faces and edges. You can select a surface when a procedure is expecting a face; for example, when you are applying distributed loads, such as pressure loads, and defining contact interactions. You can select an interior surface; for example, when you are using the solid offset mesh tool.

See Also
Selecting interior surfaces
Using the Set and Surface toolsets
In Other Guides
Defining Contact Pairs in Abaqus/Standard
Defining Contact Pairs in Abaqus/Explicit
Mechanical Contact Properties

When you create a surface on a shell model, you must select which side of the surface is the desired face; you can also select both faces. Similarly, if you create a surface on a wire model, you must select which end of the wire is the desired face; you can also select the circumference of the wire. For more information, see Specifying a particular side or end of a region.

You can define a surface that includes edges of a shell or element edges. You can use edge-based surfaces in Abaqus/Explicit general contact interactions. You can also use edge-based surfaces to tie two shells along two edges or to tie two shells that intersect to form a T.

You can create two different types of surfaces:

Geometry surfaces

Create a geometry surface by selecting geometric objects (faces and edges) from native or imported geometry. When the analysis input file is created, the surface definition in the input file specifies the element edges (in the case of axisymmetric part instances) or faces that are associated with the surface geometry.

Mesh surfaces

Create a mesh surface by selecting element faces (for three-dimensional regions) or edges (for two-dimensional regions) from meshes. Adding surfaces to the mesh allows you to request output or add loads to specific areas without deleting the mesh and partitioning the geometry. However, native element faces or edges within mesh surfaces may be invalidated or the content may change if you make any changes to the mesh—including regenerating the mesh from replay or journal files.

If you rename or delete a surface, any objects associated with the surface, such as loads or interactions, become invalid. However, if you change the name of a renamed surface back to its original name or if you recreate a deleted surface using its original name, objects associated with that surface are restored.

If you use the Virtual Topology toolset to create virtual faces and edges, you can select those virtual faces and edges when you create sets and surfaces. In addition, if an existing set or surface contains an edge or vertex that you ignored using the Virtual Topology toolset, the edge or vertex is removed from the set or surface. Similarly, if an existing set or surface contains faces or edges that you combined, Abaqus/CAE replaces the original faces and edges with the new combined faces and edges. This is true only if all of the faces and edges that you combined are members of the same set. For more information, see What can I do with a part or a part instance containing virtual topology?.