Self-intersection checks are tests used to help ensure that complex geometry you create in ABAQUS/CAE is valid for analysis. If faces of a feature intersect other faces of the same feature, ABAQUS/CAE displays a warning that there are invalid intersections and does not create the feature. A feature that intersects itself may not be meshable and may cause problems with the analysis. ABAQUS/CAE allows you to check for self-intersection during feature creation; however, the checking process will slow down creation of the feature. In addition, checking for self-intersection will slow down regeneration of the feature. The time required to complete the tests varies with the complexity of the feature you are attempting to create or regenerate.
The Feature Options dialog box allows you to toggle self-intersection checks on and off. Perform self-intersection checks is toggled off by default. In general, self-intersection is possible only when you are creating features with complex geometry, such as loft features (for more information, see What is lofting?, Section 11.14, and Self-intersection checks, Section 11.14.4). If you know that your features do not self-intersect or if you plan to remove the self-intersection during a subsequent operation, you can leave Perform self-intersection checks toggled off to speed up feature regeneration.