Context: If Abaqus reports that the volume of an imported part is negative, it means that the solid has been turned inside out. The Repair normals tool 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 normals tool will align all the selected normals on a shell part. If the face normals are already aligned, this tool will flip all the selected normals so that they remain aligned but point in the opposite direction. Note:
Abaqus/CAE does not flip normals that have been assigned to shell faces manually using the Element Normal assignment option in the Property module. When you perform repairs of non-manifold shell parts, you cannot flip the normals for all of the faces in the part in a single operation; you must select each face individually to flip the direction of its normal. Performing a query using the Shell element normals option from the Query dialog box can help you assess the orientation of the face normals before you repair your shell part. 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. The operation to repair face normals is stored as a feature of the part; therefore, you can use the Model Tree to delete or suppress the operation. |