3d cad model validation
TRANSCRIPT
Doug CheneyCADIQ Product Manager
CAD Interoperability ConsultantITI TranscenData
3D CAD Model Validation
Slide 23D CAD Model Validation
Presentation Outline
ContextIntroductionsBusinessEngineering
Validation OverviewExamplesQuality and confidenceTechnologies
Validation ApplicationsMigrationDesignReleaseChangeArchival
Future Directions
Slide 33D CAD Model Validation
Introductions
ITI TranscenDataPrivate, debt-free, profitable U.S. company since 1983Interoperability solutions business in International TechneGroup Inc.“Transcend above your data problems”…or “Smooth interoperability is a transcendental experience”
PresenterMechanical engineering educationCAD model quality consulting (12+ years)Father of CADIQ product (“CAD Interoperability Quality”)Global perspective as a youth and a professional
Slide 43D CAD Model Validation
Business Context
Global CompetitionTime to marketNarrow profit marginsRapid innovation
Global CorporationsIndustry consolidationEngineering out-sourcingMulti-national supplier base
Government RegulationQuality controlCertificationTraceabilityEnvironmental control
Slide 53D CAD Model Validation
Engineering Context
Complex SystemsMulti-disciplinary integration (MCAD + ECAD + …)Multi-disciplinary optimization (CAD + CAE + CAM + PDM + …)Multi-system environment (CATIA + NX + Pro/E + …)Extreme reliability (air, space, battlefield, medicine …)
Model-Based Engineering and Manufacturing3D model is the masterMinimal drawing dataModel used directly in downstream applications
Long-term Retention10, 50, 100 years … “life of the state”Document recoveryModel reuseHardware and software obsolescence
Slide 63D CAD Model Validation
Legacy Migration Validation
CAD A CAD B
?
Half of this model was lost after migrating the feature definition
Slide 73D CAD Model Validation
Design for Manufacturing Validation
CAD
!
CAE / CAM
This blend has a sharp cut that is not
design intent
Slide 83D CAD Model Validation
Design Release Validation
CAD A
CAD B
CAD C
CAD D
STEP
Minor topology change
Major quality change
Major shape change
Slide 93D CAD Model Validation
Engineering Change Validation
?!
CAE / CAM
Rev A
Rev B
Change to highlighted bend caused
unintentional change in location of nearby
features
Released Model Engineering Change
Slide 103D CAD Model Validation
Long-Term Archival Validation
Revolved faces are lost during STEP export
Native Design Model STEP Archive Model
Present CAD
!Future CAD
Archival10 – 100 years
Slide 113D CAD Model Validation
Risk of Unacceptable Model Changes
High Risk
Low Risk
Engineering change (human error)Manual rebuild/remastering
Feature translation (interpretation differences)Regenerate in new CAD release
BREP healing (minor modifications)STEP/IGES file importDirect BREP translation
STEP/IGES file export (model structure issues)Save in new CAD release (database changes)
Slide 123D CAD Model Validation
Validation Improves Quality
Early Warning SystemFix problems before they fester
Continuous Quality ImprovementDefects / opportunities for six sigma metricsJustify best practicesEliminate worst practices
Identify Source of ProblemLow-quality legacy dataLegacy modeling techniquesWorst modeling practices (short cuts)Complex 3D modeling obscured by shaded graphics & high-level features—often with unrealistic time pressureRevisions by other designers
Slide 133D CAD Model Validation
Validation Increases Confidence
Demystify CAD models to improve interoperabilityValue of legacy data for design reuseQuality of design data for downstream reuse
Foundation for trustQuality control between organizations
Monitor dynamic technologiesHardware improvementsSoftware upgradesSystem conversionsEmployee changes
Minimize unknown risk“What we do not know is most important”
Slide 143D CAD Model Validation
The Business Challenge of CAD Validation
All too often the organization that needs to spend money on CAD validation is not the organization
that will benefit from the results.
Slide 153D CAD Model Validation
Validation Methodology Comparison
ADVANTAGESManual Inspection
Uses existing toolsSimple to mandate between organizations
External CAD ApplicationSimple software architectureShorter analysis times
Integrated CAD ApplicationPrecise evaluation of native dataCorrelation with design featuresRapid support for new releasesFamiliar user interface
DISADVANTAGESManual Inspection
Labor intensiveError prone – IncompleteMind numbing
External CAD ApplicationData conversionModel evaluation differencesDelayed support for new releasesUnfamiliar 3D graphics interface
Integrated CAD ApplicationComplex software architectureLonger analysis times
is the only multi-CAD integrated validation tool
Slide 163D CAD Model Validation
Validation Technology Comparison
Two sources of potential differencesCAD model (data)Modeling kernel (evaluators)
Two validation tool architecturesExternal CAD application
Translate is translated before validationExternal, non-native modeling kernel evaluates the model
Internal CAD applicationNo modification of native dataInternal modeling kernel evaluates the model (same as for creation)
Master model validation requirementsWhy risk “false” differences?Native modeling kernel changes are critical to discover
These undermine the foundation of your master model strategy
Slide 173D CAD Model Validation
Optimal Model Comparison Strategy
NOT simple “cloud of points” (e.g. tessellation data)Difficult to balance performance with model coverageMany false changes reported for complex modelsDifficult to interpret the results
Top-down, PMI-based model comparisonMatch high-level geometric entities by type
Report lost, added or moved entitiesCritical for mixed models (solids + surfaces + curves)
Match topological facesSplits, merges, rotations, ...Identify which face sets “should” be compared
Sample native faces based on typeSize, complexity, geometric form, GD&T controls
Measure deviationsReport unacceptable and “near-miss” deviationsUse GD&T controls to intelligently adjust the deviation thresholds
Slide 183D CAD Model Validation
Legacy Migration Validation (Part 1)
The shape of this bend changed significantly…
Legacy Model Migrated Model
Slide 193D CAD Model Validation
Legacy Migration Validation (Part 2)
…consequently, the location of this datum hole shifted
Legacy Model Migrated Model
Slide 203D CAD Model Validation
Legacy Migration Process Evaluation
STEP TranslationMinor changesbut no features
Feature TranslationMajor changes
Manual RemasteringUnintentional changes
Legacy CAD Current CAD
Which process?
Slide 213D CAD Model Validation
Design for Manufacturing Validation
The end of this rib is only partially attached
Slide 223D CAD Model Validation
Design for Manufacturing Validation
Unrealistic (ambiguous) features in models must be interpreted by downstream users
Different interpretations can affect part quality
DesignModel
Prototyping Model
AnalysisModel
Rework
Rework
ManufacturingModel
Slide 233D CAD Model Validation
Design for Manufacturing Validation
Native Design Model
Slide 243D CAD Model Validation
Design for Manufacturing Validation
Simulation approved the design
Manufacturing produced initial parts from native model
All parts failed during final testing
Caused last-minute schedule delay and retooling
Test Part Fatigue Failure
Slide 253D CAD Model Validation
Design for Manufacturing Validation
Unrealistic feature(zero thickness)
Testing failure(missing material)
Native Design Model
Manufactured Part
Slide 263D CAD Model Validation
Design for Manufacturing Validation Statistics
Quality Assessment
Process Quality Control
Slide 273D CAD Model Validation
Engineering Change Validation
This is a subtle change that is difficult to detect manually and may not be intentional
Released Model Engineering Change
Slide 283D CAD Model Validation
Engineering Change Documentation
Released Model Engineering Change
Each shape change should be clearly documented for efficient downstream reuse
Slide 293D CAD Model Validation
Long-Term Archival Process Comparison
The STEP model is precisely equivalent
IGES model is shifted by 0.5 inch
(13 MM)
Native CAD Assembly
Slide 303D CAD Model Validation
Long-Term Archival Validation
The highlighted part’s position within the assembly has changed
Native CAD Assembly
CAD Assembly after STEP export and re-import
Slide 313D CAD Model Validation
CAD Translation Space-Time Continuum
CAD ARev 2
CAD BRev 5
CAD ARev 200
CAD BRev 500
Time
Space
Present FutureLong-term archival translation problems
are unknowable.But they can be indicated by
present CAD-to-CAD translation problems.
Slide 323D CAD Model Validation
STEP Translation Validation
Quality defects and shape changes caused by extreme gap in native model
LegacyModel
STEPModel
TranslatedModel
Not a Solid
Slide 333D CAD Model Validation
STEP Translation Validation
Quality defects and shape changes caused by poor surface approximation during STEP export
LegacyModel
STEPModel
TranslatedModel
Not a Solid
Slide 343D CAD Model Validation
Long-Term Archival Validation Properties
Sampling points evaluated on the native model can be stored in the STEP model to enable precise
validation after retrieval into a future CAD system
Native Design Model STEP Archive Model
Slide 353D CAD Model Validation
Validating More Than Just Geometry
Collaboration Model ValidationCAD to 3D PDFCAD to JT
Assembly StructureDuplicate instances, interferences, narrow spacesStructure changes
Product Manufacturing Information (PMI)3D geometric dimensions and tolerances (GD&T)Annotations (notes)Model attributes
Questions?Doug Cheney
CADIQ Product ManagerCAD Interoperability Consultant
ITI TranscenData