Hi All,

When geometry is imported into Abaqus/CAE using a neutral format file such as .sat, free edges lying close to one another are stitched upon choosing auto-repair after the import. Sometimes, there remain many edges that have not been stitched because of the behavior of stitching. There are two types of stitching and for both, only the edges that are lying right next to each other are stitched:

1. Manifold stitching: Only manifold edges are stitched. Manifold edges are those whose stitching will result in having not more than two faces on the edge.
2. Non-manifold stitching: is also possible. An edge that is the result of stitching more than two faces on it is called a non-manifold edge.

Edges that are not close to any other edges, but close to some face will not be stitched. For this the imprinting operation is required. Imprinting creates an edge on the face it is close to and then stitches the edge with this newly created edge. This is similar to Boolean.

CAE does not perform imprinting upon importing, causing some edges to remain free. This is as designed- you may file an RFE if necessary. The Face Extend operation in Geometry Edit can be used to manually merge free edges to faces. The edge must lie on the face completely or the extend operation of ACIS will fail.

Thanks,

Preeti