Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A Segment. A section of a line or curve bounded by two end points and characterized by a single mathematical expression. Sew. The process of combining discrete faces into a single shell or solid model. Shell. An open set of sewn faces (i.e. a boundary representation) that is not closed. Sketch. A two-dimensional profile containing parameters used in a feature. Solid. A set of sewn faces (boundary representation) enclosing a volume. Spline. A special type of piecewise polynomial curve whose flexibility mimics a thin strip of wood or metal originally used in shipbuilding and aircraft lofts.
Standard For The Exchange Of Product Data (STEP). The informal name for ISO standard 10303 Product Data Representation and Exchange. Structure. The relationships among parts in a product assembly or among features in a feature- based part. Surface. A mathematical representation of a flat or curved bounded space having length and width but no thickness. A surface may consist of multiple surface patches adjacent on all internal edges. Threshold. The minimum or maximum measured value that indicates the existence of a quality defect.
For example, the distance threshold for evaluating a gap between a surface and its trimming curves implies that if the maximum distance between the surface and the curves is greater than or equal to the specified minimum value, then the gap shall be considered a quality defect. Tolerance. The maximum allowable deviation between any point on a geometric entity and its theoretical true position. 63