ANSYS Discovery SpaceClaim

Shared topology in ANSYS

Discovery SpaceClaim can share topology (face, edge, and vertex connections) between touching or intersecting bodies and surfaces in designs that are transferred to ANSYS.

Shared topology is the only way to achieve a conformal mesh where bodies meet, and is the only way to be certain that the intersection of bodies is meshed perfectly.

Shared topology also applies to volume and surface bodies that are completely inside of other volume or surface bodies. This situation is common in analyses involving fluid flow.

The Shared Topology settings are:

• None (default) does nothing to geometry during transfer to ANSYS/Workbench
• Merge is intended only for Baffles used in CFD analysis:
  • It merges surfaces that are fully embedded within a solid. SurfaceTwo dimensional object that has no thickness (as opposed to a face, which is part of a three-dimensional object). A surface has area but no volume. See FaceSide or other surface of a solid. Some examples are the inside surface of a hole or the six sides of a rectangular solid. See Surface.. edges that lie on the solid are valid. Surfaces that intersect the solid are not valid and must be trimmed before executing Shared Topology.
• Share imprints and merges all bodies in the components and transfers the result to ANSYS as a multi-body part
• Group groups all bodies in a component into a multibody part, but does NOT merge or share faces and edges of the bodies with each other

To create a group of parts that share topology

1. Create a component the default setting is None, which treats multi-body parts as a sub-assembly of independent parts (i.e. no sharing).
2. Set the Share Topology property to Merged, Shared, or Group in the properties panel of the component
3. Place any solids, surfaces, beams, or components that you want to share topology into this component.

For ANSYS 15.0 and later, Shared Topology set to Merged applies to the following cases:

• Bodies that are touching each other (same as Shared)
• Surface bodies that are intersecting each other (same as Shared)
• Volume bodies that are completely inside of other volume bodies. For example SolidObject that encloses volume. A surface becomes a solid if it encloses volume. A is completely inside of Solid B which is completely inside of Solid C. Solid A will share topology with Solid B and Solid B will share topology with Solid C.
• Surface bodies that are completely inside of volume bodies. For example Surface A is completely inside of Solid B which is completely inside of Solid C. Surface A will share topology with Solid B and Solid B will share topology with Solid C.
• Any combination of the above four cases.
• Not Supported - Cases where volume bodies partially intersect each other or surfaces extending outside of volume bodies.

For ANSYS 17.0 and later, Shared Topology set to Group will group all bodies in a component into a multi-body part in ANSYS/Workbench. It does NOT merge or share faces and edges of the bodies with each other.

• For legacy databases, the NONE option maps to Group in the latest version.

Beams that are in the same component and have the same properties (i.e. Cross SectionDesign2D or 3D model that contains at least one top-level component. mode in which you edit solids by working with their edges and vertices in cross-section. ViewOrientation settings that you can apply to your design, including spin, pan, and zoom. You can adjust these settings individually or you can apply one of the following preconfigured views: Trimetric, Isometric, Top, Bottom, Front, Back, Right, Left. You can also select Snap View and click a face to view it head-on. is cut away to show interior detail., Anchor, MaterialProperty that you can assign to an object, consisting of material name and attributes such as density and tensile strength.), are transferred to Workbench as follows, when Shared Topology is set to Merge, Share, or Group:

• Orientations of the connected beams may be different (e.g. rotated relative to each other) as long as ALL other cross section properties match.
• Beams connected end-to-end are one body with multiple edges.
• Beams that from "T" and "X" intersections are single bodies but the intersections create additional edges in each body. The example below is two bodies with four edges.

  

• Connected Beams that intersect themselves are a single body but the intersections create additional edges in the body. The example below is one body with five edges.

  

ANSYS 13.0 through 15.0

• If a component has the Shared Topology property set to Shared (or Merged in ANSYS 15.0 and 16.0), then that component and all components beneath it become a share group.
• The Shared Topology property of components lower in the structure are ignored, so you can't use them to create sharing exceptions.
  • For example, if you set Shared Topology to true for the root component, then the entire model will be one share group.
• The name of the component node is the name of the component from which recursive sharing starts.
• The bodies under this node are listed with full path names through the assembly, such as Axle Sub-Assy (Front)\Wheel (Left)\Solid, using component names in parentheses if they are present.
• You can have multiple distinct share groups, but a body can only belong to one group.

See the Shared topology tutorial for hands-on experience with shared topology. See ANSYS online help for detailed information about how ANSYS handles multi-body parts and shared topology.

To set shared topology for ANSYS

Put the bodies anywhere under a component that has its Shared Topology property set to Shared (or Merged in ANSYS 15.0 and 16.0), including a sub-assembly (regardless of the sub-assembly's Shared Topology setting).

This property can be found in the properties panel when you select one or more components in the Structure treeDisplay in the Structure panel that shows you each of the objects in your design. You can expand or collapse the nodes of the tree to view the objects. You can rename objects, create, modify, replace, and delete objects, as well as work with components..

The Shared Topology property on Parent componentA component upon which other components depend. For example, in a block with a hole, the block is the parent and the hole is the child. is set to true, so the solids inside the shaded area are shared.

To prevent shared topology in ANSYS

Place solids in a component whose Shared Topology property is set to None, and whose parent components also have this property set to None.

Examples

ANSYS meshes two blocks with shared topology. The blue block will gain a new imprinted face which will be shared between the green and blue blocks. Notice how the nodes of the mesh line up along the bottom of the smaller block.

ANSYS creates separate meshes for two parts because they are in different components and the root part has Shared Topology set to None.

The mesh for shared topology is not the same as merged geometry. Here the boxes are merged, and you can see that the mesh is different than it is for two bodies with shared topology.