9.10. Spot Welds

You use the spot weld feature to connect individual solid and surface body parts together to form solid or surface body model assemblies. Structural loads are transferred from one specific body part to another via spot weld connection points. This enables you to simulate of solid and surface body model assemblies.

Weld Group (Beta Feature)

Using a current beta object, Weld Group, you can manage a group of spot welds that connect multiple surface body parts. This object provides properties to either import predefined spot welds from a text file or to manually create individual spot welds.

Spot Weld Details

Spot welds are usually defined in the CAD system and automatically generated upon import, although you can define them manually in Mechanical after the model is imported. Spot welds become hard points in the geometric model. Hard points are vertices in the geometry that are linked together using Beam Elements during the meshing process.

Spot weld objects are located in a Connection Group folder. When selected in the tree, they appear in the Geometry window highlighted by a black square around a white dot on the underlying vertices and include an annotation.

If a model contains spot weld features in the CAD system and the Auto Detect Contact On Attach is turned on in the Workbench option, Tools > Options>Mechanical, then Spot Weld objects are generated when the model is read into the Mechanical. Spot weld objects will also get generated during geometry refresh if the Generate Automatic Connection On Refresh is set to Yes in the Details view of the Connections folder. This is similar to the way in which Mechanical automatically constructs contacts when reading in assembly models and refreshing the geometry.

You can manually generate spot welds as you would insert any new object into the Outline. Either insert a spot weld object from the context menu and then pick two appropriate vertices in the model, or pick two appropriate vertices and then insert the spot weld object.

You can define spot welds for CAD models that do not have a spot weld feature in the CAD system, as long as the model contains vertices at the desired locations. You must define spot welds manually in these cases.

Spot Weld Application

Spot welds do not act to prevent penetration of the connected bodies in areas other than at the spot weld location. Penetration of the joined bodies is possible in areas where spot welds do not exist.

Spot welds transfer structural loads and thermal loads as well as structural effects between solid, surface, and line body parts. Therefore they are appropriate for displacement, stress, elastic strain, thermal, and frequency solutions.

The DesignModeler and SpaceClaim applications can be used to generate spot welds. The only CAD system whose spot welds can be fully realized in Ansys Workbench at this time is NX. The APIs of the remaining CAD systems either do not handle spot welds, or Ansys Workbench does not read spot welds from these other CAD systems.


Note:  Because a Spot Weld is a remote boundary condition, it can make use of remote points that were either specifically defined or created internally by the application. As a visual check, you can display connection lines between your scoping and the remote point by selecting the Remote Point Connections option of the Style group (Display tab).