Detect interferences and coincident faces

Learn how to use the Interference command to detect interferences and coincident faces in Fusion.

On the toolbar, select Inspect > Interference .
Select the bodies or components you want to evaluate for interferences.

The Interference dialog displays.
Optional: Check Include Coincident Faces to detect coincident faces between bodies.
Click Compute .

One of the following three results occurs:
- A pop-up message appears and states, No interferences detected: This is the result if there are no interferences, and either or the following conditions exists:
  - The Include Coincident Faces option is not checked, or
  - The Include Coincident Faces option is checked but there are no coincident faces among the bodies that were evaluated.
- An Interference Results dialog appears, but it lists only zero-volume Groups of components: This is normal if you activated the Include Coincident Faces option, there are coincident faces between the evaluated bodies, and there is no overlapping of evaluated bodies.
- An Interference Results dialog appears listing one or more Groups of components or bodies with a positive, non-zero interference Volume. If you activated the Include Coincident Faces option, the list may also contain coincident faces (zero-volume results), as previously described.
Note: The Show All Interferences checkbox in the Interference Results dialog toggles the visualization of the interferences. The option is enabled by default. Different interference groups are highlighted with a rotating set of colors. Coincident faces are outlines but not highlighted (but only when the Include Coincident Faces option is enabled). When Show All Interferences is disabled, interference groups are highlighted one at a time when you click on a row of the table.
If an interference is detected, and you wish to remove it now, continue to step 6 in the next section. Otherwise, click Cancel to dismiss the Interference dialog.

Remove interferences (when supported)

Requirements: Automatic removal of interferences between bodies or components is supported for the following conditions:

From the Design workspace, Solid or Surface tab or Form contextual environment, interference removal is only supported for the Direct modeling mode.

When Capture Design History is enabled (Parametric modelling mode), the Interference tool only reports overlapping components and bodies (and optionally, coincident faces). Interference removal is not available for parametric models in these three workspaces.
Within the Simplify workspace, all model changes are parametric. However, automatic interference removal is supported. In other words, the Interference tool in the Simplify workspace can remove body-to-body and component-to-component interferences from all models.

The following procedure is applicable for the direct modeling mode (in any modeling workspace) and for all models in the Simplify workspace. The interference removal procedure continues from the preceding interference detection procedure:

If there are two or more interference Groups listed, and you do not want to remove all of them: Deactivate the Remove Volume checkboxes for the interferences you do NOT want to correct at this time.
Notice that the table includes a Target (Cut) column and a Tool (Keep) column. These columns indicate from which component interference material is removed, and which component retains the interference volume. Optionally, click the swap button to swap the Tool and Target components.
Click OK to complete the interference removal.

Important: If interference exists because of an error in the production model, you should consider whether it would be better to correct the geometry in one of the modeling workspaces. For example, a body dimension or a constraint may be incorrect. However, in some cases, interferences might be normal. Consider an assembly of two flanges with a gasket between them. The gasket part may be modeled using its original, uncompressed thickness (so that its detail drawing is correct). However, when assembled, the gasket compresses to a thinner dimension. If the correct expected gap between the flanges is modeled, then interference exists between the nominal gasket and flanges. In such cases, you should leave the production geometry alone and remove the interference in the Simplify workspace. Changes made using Simplify tools do not affect the production model but are simulation-specific.