Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A Effects of condition on CAD data quality: Design and drafting: May cause incorrect mass properties calculations, increases file size unnecessarily, may be indicative of unintended errors, may produce unintended quality defects during future operations, may cause incorrect geometry to be selected during editing, may cause unexpected shape changes during edits. Embedded solids may be desired to model differing material types within a solid object. For example, a thermoplastic part may be reinforced with a steel core. Data exchange: Models may fail to sew after translation. Finite element analysis:
May produce excessive or unwanted mesh elements. Numerically controlled manufacturing: Tool-path generation algorithms may gouge the work piece. Recommended correction: Delete the embedded solid(s) unless required by the design. C.7.7.2. Intersecting Shells (G-SO-IS). Definition: A pair of shells intersect one another in a solid body. The logical value of this criterion is true if no shells intersect within the solid within the specified limits of precision. Effects of condition on CAD data quality: Design and drafting: Solid models with self-intersecting shells may be unable to be manufactured or indicative of unintended design errors. Data exchange:
May cause trimming problems with faces, failure of solid models to sew. Finite element analysis: May produce unrealistic models. Numerically controlled manufacturing: Gouging and other unsatisfactory cuts may occur. Recommended correction: Rebuild the models without self-intersecting shells. 120