Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A Recommended correction: Reverse normal directions of the shell or selected faces as necessary. C.7.6.7. Free edge (G-SH-FR). Definition: An edge curve is used by only one face in a shell. The criterion is true if no edges are used by fewer than two faces. Effects of condition on CAD data quality: Design and drafting: Non-manifold objects can’t be physically realized. Some CAD software can’t display non-manifold geometry. Data exchange: Some target applications don’t support non-manifold geometry. Finite element analysis: Mesh generation may fail due to non-manifold conditions. Numerically controlled manufacturing:
Tool paths may fail because of non-manifold conditions. Recommended correction: Revise shell faces to eliminate free edges. C.7.6.8. Over-used edge (G-SH-NM). Definition: An edge curve is shared by more than two faces in a shell. The criterion is true if no edges are used by more than two faces. Effects of condition on CAD data quality: Design and drafting: Some CAD software can’t work with non-manifold geometry. Data exchange: Some target applications don’t support non-manifold geometry. Finite element analysis: Mesh generation may fail due to non-manifold conditions. 118