Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A Finite element analysis: Automatic mesh generation may fail because software can’t recognize curves with embedded curves as continuous Numerically controlled manufacturing: Tool path generation may fail because software can’t recognize continuous curves. Recommended correction: Delete one of the double elements with the fewest dependent relationships. Reassign relationships, if any, to the remaining curve. C.7.1.8. Excessively high-degree Curve (G-CU-HD). Definition: Polynomial curve is of excessively high degree, integer value n. Effects of condition on CAD data quality: Design and drafting:
High-degree curves are susceptible to unwanted undulations and unpredictable behavior when small changes are made. Data exchange: The receiving system may be incapable of interpreting the high degree curves. Translators may fragment the curve into multiple tiny or discontinuous segments. Finite element analysis: Automatic mesh generation may fail because software can’t recognize high degree curves. Discontinuous segments may produce excessively fine mesh elements. Numerically controlled manufacturing: Tool path generation may fail because software can’t recognize high-degree continuous curves. Unwanted undulations may occur in the finished work piece. Recommended correction:
Avoid using polynomial curves of high degree. Subdivide high-degree curves into sets of adjacent curves with lower degree. C.7.1.9. Fragmented curve (G-CU-FG). Definition: The curve contains too many segments, integer value N. This condition may be caused by data translation that approximates a higher degree curve with a set of lower-degree curves. 89