Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A Numerically controlled manufacturing: Tool path generation may fail because software can’t recognize high-degree surfaces curves. Unwanted undulations may occur in the finished work piece. Recommended correction: Avoid using polynomial surfaces of high degree. Subdivide high-degree surfaces into sets of adjacent surfaces with lower degree. C.7.2.13. Fragmented surface (G-SU-FG). Definition: Number of patches in the surfaces, N, exceeds recommended value.
The condition may be caused by translation processes that approximate high-degree polynomial surfaces with surfaces of lower degree or by the merging of surface elements with varying segmentation. Effects of condition on CAD data quality: Design and drafting: An excessive high patch count indicates that the surface definition is too complex. Fragmented surfaces are hard to modify. Data exchange: The receiving system may be incapable of accepting surfaces with excessive numbers of patches. Finite element analysis: Automatic mesh generation may fail because software can’t cope with high patch counts. Fragmented surfaces may produce excessively fine mesh elements.
Numerically controlled milling: Tool path generation may fail because software can’t handle high patch counts. Tool-path software may run too slowly. Recommended correction: Avoid creating surfaces with high patch counts. Divide fragmented surfaces into sets of adjacent surfaces with fewer patches in each. 99