Introduction

This document defines the requirements on a digital archive to preserve for the long term the 3D explicit geometry of single CAD parts. The goal is to preserve the 3D information without loss with respect to the geometry produced by the original CAD system, following the principles laid down in NAS 9300-003 'Fundamentals and Concepts', including the use of an open data format.

In scope

The following is in scope of this part of NAS9300:

• Business specification for long term archiving and retrieval of CAD 3D explicit geometry (see chapter 5);

• Essential information of CAD 3D explicit geometry to be preserved (see chapter 6);

• Data structures detailing the main fundamentals and concepts of CAD 3D explicit geometry (see chapter 7);

• Verification rules to check CAD 3D explicit geometry for consistency and data quality (see chapter 8);

• Validation rules to be stored with the CAD 3D explicit geometry in the archive to check essential characteristics after retrieval (see chapter 9).

Note: This includes the geometrical external shape resulting from CAD disciplines 3D entities (E.g., 3D Structural componenets, 3D Tubing, 3D electrical harness, 3D composite, etc.).

Out of scope

The following is outside the scope of this part of NAS9300:

• The formal definition of validation and verification rules to check 3D explicit geometry for consistency and data quality using a machine-readable syntax;

• Implicit or parametric geometry;

• Geometric Dimensioning & Tolerancing (GD&T), Product & Manufacturing Information (PMI);

• Assembly structures