Abaqus/CAE tries to change the internal definition of edges, faces, and cells into a simpler form that can be represented analytically. For example, a face that is nearly planar will be converted to an equation that represents the plane. Converting to an analytical representation usually provides the following advantages:

• Processing of the part is faster.

• The converted entity is available during feature operations. For example, the extrude operation requires a planar face and a linear edge.

• The geometry is improved.

• If you subsequently need to stitch the part, the stitching operation is more likely to be successful.

Abaqus/CAE offers two methods to convert entities to precise geometry:

• If you choose Tighten Gaps, Abaqus/CAE attempts to improve the precision of the faces, edges, and vertices in your model. This method is faster but does not perform a full computation of the geometry.

• If you choose Recompute Geometry, Abaqus/CAE tries to change neighboring entities so that their geometry matches exactly. Recomputing geometry usually results in precise geometry; however, this operation can be lengthy and increases the complexity of the imported part, which means that processing of the part is slower. Moreover, if the part contains many complex surfaces, converting to a precise representation is likely to fail. If possible, you should return to the CAD application that generated the original file and increase the precision.