Methods for editing faces

You can remove selected faces (including chamfers, fillets, and holes) from a three-dimensional solid or shell or from a two-dimensional planar part. After you have selected the faces to remove, Abaqus/CAE looks for adjacent faces that define a feature. You can remove the entire feature, or you can remove only the selected faces. When you remove one or more faces from a three-dimensional solid part, Abaqus/CAE converts the part to a shell.

You can create a face on a three-dimensional part by selecting one or more edges of the new face. Abaqus/CAE loops through the adjacent edges and calculates the location of the new face. If you selected multiple edges that are not connected by a common loop, Abaqus/CAE creates multiple faces, one for each loop of edges. Abaqus/CAE creates the new faces as shells. If the new shells form a closed part, you can use the solid-from-shell tool to convert the part to a solid.

In some cases Abaqus/CAE may not be able to accurately recreate some of the faces when you import a part. For example, a planar face may appear wavy or distorted, or Abaqus/CAE might create small faces that have a large impact on the mesh density. You can select connected faces, and Abaqus/CAE replaces them with a single face. The new face has minimal faceting and will be smoother than the original faces. Figure 1 illustrates the effect of replacing selected faces.

Figure 1. The effect of replacing selected faces.

Alternatively, you can replace the selected faces with a single face that is formed by extending neighboring faces. You can use this tool to remove bosses and small details from imported parts, as shown in Figure 2.

Figure 2. The effect of replacing selected faces and extending neighboring faces.

You can repair selected small faces. Abaqus/CAE removes the small faces and edits the adjoining faces to create a closed geometry. Figure 3 illustrates the effect of repairing small faces.

Figure 3. Repairing small faces.

A sliver can be thought of as a small, sharp piece of extra material. You can remove an unwanted sliver from a face of a three-dimensional solid or shell or from a two-dimensional planar part. You must select the face containing the sliver to remove and two points from the face. Abaqus/CAE draws a line between the two points that divides the selected face into two regions. The first region is the face that will remain; the second region is the sliver that will be removed. Figure 4 illustrates the effect of removing a sliver.

Figure 4. Removing a sliver.

You can repair the face normals of shell and solid imported parts, and you can perform these repairs on either manifold parts (parts in which every edge is shared by only one or two faces) and non-manifold parts. The tool has different uses for solid and shell parts.

Solid

In rare cases the Query toolset reports that the volume of an imported solid part is negative because the face normals indicate it was inside out in the CAD system from which it originated. The Repair face normals tool will flip the normals and turn the solid right side out.

Shell

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.

Note:

The element normal orientation, which is specified using the Element Normal assignment in the Property module, specifies the relative element normal with respect to the geometry normal. These element normals will be updated using the new geometry normals after the Repair face normals operation.

When you perform repairs of non-manifold shell parts, you cannot align the normals for all of the faces in the part in a single operation; you must select faces individually to flip the direction of their normals. You can perform a query using the Shell element normals option from the Query dialog box to assess the orientation of the face normals before you repair your shell part.

You can create faces on a three-dimensional part by selecting the faces to be offset then specifying an offset distance or selecting target faces and a distance calculation method. The offset direction is opposite to the face normal direction for the source face, and offset can be positive or negative. Abaqus/CAE creates the new face using the same process as that used for offsets in the Sketcher (for more information, see Offsetting objects).

You can extend existing faces by specifying an extension distance or selecting target faces to control the extension distance. Abaqus/CAE replaces the existing faces with the extended face feature.

You can create new faces that blend the contours of existing edges in the model to form faces between those edges. You can choose to create the new faces by using tangency to existing faces at each edge, by calculating the shortest path between the edges, or by specifying a wire shape as the path.

You can create a new geometric face from orphan element faces. Abaqus/CAE creates a new geometric face based on the node positions of the selected element faces. Vertices are created at edge nodes where there is a significant change in the element edge direction.