You can repair the face normals of shell and solid imported parts. The part must be a manifold, meaning that an edge is shared by only one or two faces.
If ABAQUS reports that the volume of an imported part is negative, it means that the solid has been turned inside out. The Repair face normals will flip the normals and turn the solid right side out.
An imported shell part can contain faces that have normals pointing in opposite directions. The Repair face normals tool will align all the normals on a shell part. If the face normals are already aligned, this tool will flip all the normals so that they remain aligned but point in the opposite direction.
The Query toolset provides a set of geometry diagnostic tools that calculate the volume of a solid part and display the normals of shells and membranes. For more information, see “Using the Query toolset in the Part module,” Section 11.16.4. The operation to repair face normals is stored as a feature of the part; as a result, you can use the Model Tree to delete or suppress the operation.
To repair face normals:
From the main menu bar, select Tools
Repair.
ABAQUS/CAE displays the Geometry Repair Tools dialog box.
Tip:
You can also repair face normals using the 
tool, located with the repair tools in the Part module toolbox. For a diagram of the repair tools in the toolbox, see “An overview of repair techniques,” Section 47.2.
From the dialog box, select Repair face normals and click OK.
ABAQUS/CAE repairs the face normals.
If you have finished repairing the part, you should check its validity by clicking mouse button 3 on the part in the Model Tree and selecting Update validity from the menu that appears.
