When a CAD Source part is used to define a Simcenter 3D Motion model, it’s possible that not all of the CAD features are shown. Datums, sketches, and even 2D surfaces may not appear in the Motion simulation file even though they appear in the CAD part file.
This can cause an issue then these geometric features are needed to define motion elements. In the above model, a 2D surface is required to define the contact surface for a sphere-to-extrusion contact element between the pulley and the cable elements. The contact element cannot be completed without the surface to select.
This issue is very often caused by having the wrong reference set selected in the part file. To resolve this, first open the CAD Source part from the top of the Motion Navigator. Make sure that the Modeling Application is being used after opening the part.
Expand the component structure in the Assembly Navigator until you find the component with the missing geometry. Note that the reference sets for each component can be shown in the columns next to each component. The default reference sets are “MODEL”, “Entire Part”, and “Empty”. MODEL will show only solid and surface geometry by default. This is intended to show how the part will actually look. Entire Part will show all CAD features, while Empty will hide the whole component. There may be customized reference sets as well. Look for any sets that are not set to “Entire Part”.
To change the reference set, right click on the component and select “Replace Reference Set”. Use the drop-down menu to select “Entire Part”. This will show all of the features in the component.
The 2D surface of the pulley is now shown, along with a datum CSYS and curve:
This change will carry over to the Motion simulation file and the 2D surface will now appear and be selectable for the contact element.
You can edit or create new reference sets in the Assemblies tab in the Modeling Application. Remember that each component has its own reference set. This means that you will be changing the reference sets for the Work Part only.