Implementing Parametric CAD in STEP ???? Kenneth E. Wolsey May 16,

Parametric CAD Steps 1.Set up parametric CAD infrastructure 2.Perform conceptual design 3.Instantiate CAD models and documents for projects

Set up parametric CAD infrastructure Identify needs and get management buy-in Benchmark systems and select a vendor Purchase, install and set up systems Create internal CAD standards Perform CAD operator training Maintenance and continuous improvement

Perform conceptual design Review needs Prepare specifications Create and iterate design concepts Review and approve conceptual design Create “Family of Parts”

Instantiate CAD models and documents for projects Perform detail design Create drawings and specifications Perform design analysis and systems integration Revise drawings and specifications

Design challenges create inefficiency Workforce distribution Tool learning curves Propagation of best practices Communication of design downstream Complex design features & lean design Design changes Lack of defacto or industry tool standards for parametric CAD

Parametric CAD Strengths Create complex 3D geometry Visualize design results Interface design Interference detection Strong mathematical foundation for analysis Semi-automation of design (Family of Parts)

Difficulties with parametric CAD Long learning curve –Different than other 3D methodologies –Large training investment –Solid extrusion and subtraction methodology Difficult to identify, capture, and record design rules –Heavy focus on geometry building –Can’t affect rules you can’t see or control Difficult to create and modify 3D models –Sketch – model paradigm –Rigid design history Difficult to share –No defacto or industry standard for rule and parameter representations –No neutral file interface for rules –STEP translators export geometry only

Component Design Framework Architecture Component Design Configurator Schemas AP212 AP214 AP227 DXF SVG Component Dictionary Component Design File Knowledge base 2d CAD 3d CAD Technical Publications episTree DESIGN ®

Parametric CAD data exchange AP214 data exchange foundation Extract rules from CAD system through the native API Modify and maintain rules in a knowledge base Automatically generate CAD system updates through the CDF

Parametric CAD Examples ISE5 electrotechnical data Air force mechanical parts

Weld Lifecycle Project Objectives 1.Facilitate knowledge reuse 2.Leverage an open system architecture 3.Develop rule-based weld design software 4.Develop software to evaluate weld designs against a scorecard of best practices. 5.Develop software to enable decision support. 6.Establish an open-forum welding knowledge base

Project Team NSRP Solicitation –N Technologies to Improve Mid-tiered Shipbuilding Design and Planning Functions LCS, PMS 501, ACAT ID sponsors Knowledge Systems Solutions General Dynamics Electric Boat Bender Shipbuilding and Repair Others based on interest … Phase I, March - September

Weld Lifecycle Tasks 1.Review and analyze weld lifecycle processes 2.Specify an open systems architecture patterned after NIST work for welding data architecture 3.Evaluate AP218 for weld data translation 4.Create rule-based weld specification prototype 5.Create design checking prototype 6.Create inspection/QA prototype 7.Create shared internet knowledge base prototype

Progress to date Shipyard visits – knowledge acquisition Process analysis Architecture, system, data analysis Use case definition – Design, Planning, Inspection, Sharing Specification preparation