KBE-System and Case-Library for UG-Structures EUUG Usermeeting 2003 Peter Binde

1. CaseBasedEngineering KBE-System and Case-Library for UG-Structures EUUG Usermeeting 2003 Peter Binde

2. Content - Dr. Wallner Group - Motivation for a new Assistant System - Case Study: Automotive-Generator - Feature-Processing - Concepts of the CBE-Assistant

3. Dr. Wallner Group Service around CAD, CAE, PDM Focus on EDS-PLM Products Competences: - Process-analyses and -syntheses - Trainings and workshops - User-support and hotline - Integration-solutions and software-development

4. CaseBasedEngineering Dr. Wallner Group: - Simulation Focus on Design-Embedded Product-Simulation Training, Consulting, Support for CAE Software for Knowledge-Processing Projects shared by Industry & Research

5. Dr. Wallner Group: - The Founder‘s Vision Jens Wallner died this year by a car accident His vision: - High Quality Service, for CAD/CAE/PDM – will continue in the four Wallner-companies,that belong to the Group.

6. Motivation for a new Assistant System

7. Original Scenario Original Scenario Bördelung Scenario Bead =80N/mm2 u=0,9mm Vergleich = 72N/mm2 u=0,8mm =71N/mm2 u=0,4mm Present Situation More and more FEA becomes the designers daily work VDI Report about Adam Opel Project: - Designers do FEA themselves -

8. Deficits - Often special-knowledge is necessary - Different methods for same problems are used - Knowledge stays in the heads of specialists and key users - Examples and summarised methods are only static - Databases organize data, but do not know about the content ?

9. Storage of a new solution Retrieval of most appropriate cases Case Base Adapting knowledge to a new Solution Solution: - Store all knowledge anyone has learned in past-cases. - Reuse that knowledge Very similar to human learning Method: - Case Based Reasoning (CBR) Superior to application of rules

10. All we need is: - Two new buttons in our UG-Scenario system:

11. Questions: - How to store a solution? - How to adapt knowledge from a similar solution? - How to find the most similar cases? Store Find Case Base Answers: - Extensively use feature-processing - Store the feature-structure of successfully solved cases - Find similar cases by pattern recognition of feature-structures - Let the user interpret and adapt knowledge Adapt

12. Case Study: Automotive Generator Analysis Goals:Find Characteristics, that Contain Knowledge Develop a Structure for that Knowledge

13. Contact-Condition Solver-Parameter Design-context Part for analysis & part-properties Form-feature at result: Cutout, Blended Result-type: Stress & validation Mesh-property at result, Geometry-preparation Centrifugal-Analysis of Fan: Characteristics, that Contain Knowledge Load-type: Rotation

14. Contact-Condition Design-context Solver-Parameter Support-Condition Form-feature at result Result-type: & Validation Part for analysis & part-properties Mesh-property at result Generator-Axle under Bending-Load

15. Solver-Parameter Design-context Part for analysis & part-properties Form-feature at result: Blended Result-type: Stress & validation Mesh-property at result Acceleration-Analysis of Housing Forces, that result from contacting parts Load-type: Acceleration& Geometry applied to

16. Adjoining Parts - Form-feature - Form-feature … Adjoining Parts - Form-feature - Form-feature … … - Form-feature - Form-feature Analysis-part - Form-feature - Form-feature … … - Form-feature - Form-feature Contact Contact Face-FaceCoupling Screw (4x) Contact Stress-Validation (requested) Screw (4x) Description of the Situation and Analysis-Task by Computable Elements Effect: Acceleration

17. Project Structure for Storage of a Task Analysis-scenario Part Material Property-aggregation... Form-feature Contact Form-feature Part Form-feature Fix Load-Effects Solution-Group Property-aggregation... Form-feature Part Material Analysis-scenario

18. Description of a Solution by Computable Elements A solution contains idealization-methods and the result • Idealization of screw-connections • Neglected pre-load • Rigid Type, … • Idealization of face-coupling • Restriction of DOFs • Mesh-property in critical area • Number, quality, type of elements • Idealization of acceleration • To be neglected Result: -location, -type, -validation and -consequence • Idealization of adjoining parts • Acceleration-Force on contacting faces • Geometry-Idealization • Small feature removal • Idealization of material • Isotropic, linear Solver-Parameter

19. Feature-Processing

20. Features Model Design Characteristics A Feature is a Container for a Design Characteristic Example Feature Weld point: included information: - Group of involved elements - Connectivity to geometry - Strength requirements - Tolerances - Costs - Manufacturing processes ... Advantage: Weld point can be processed as a „weld point“.

21. Knowledge Management using Semantics and Features We try to build up models only by use of features This method automatically captures our knowledge and provides standard-solutions CAD Features: (1) Sketch (2) Revolved (3) Pocket (4) Pocket (5) Hole (6) Threads FEM Features: Fixed Face Centrifugal Load Concentrated Mass Stress Calculation Fatigue Calculation rot

22. This,Because the hole can be recognizedautomatically by all following processes Feature-Processing: Simple Example ? ? Which feature-description of a hole is preferred

23. Knowledge is captured automatically Knowledge is captured manually Extensive Usage of Feature-Processing • -The user builds a clear, short feature-structure • The user inserts further knowledge by assigning names, groups, descriptions, comments, … . Insert as much knowledge as possible to the model. Manually definition of features is also possible.

24. CaseBasedEngineering Concepts of the CBE-Assistant

25. Feature Recognition Extracts and classifies all available feature-information to an extended feature-navigator:

26. Transparency Example: Part-connections are shown completely: “Fan” is connected to “Rotator”. The involved form-features as well as contact properties are shown.

27. Feature-Attributes Properties of features can be edited

28. Manual Feature Definition Features, not supported by UG-scenario can be added: Stress-Results are validated on a Blend Form-Feature of the “Fan”.This feature is “extra” inserted by the user.

29. Meets the “designers language” Tasks / Solutions are Separated CBE feature-information merely includes task (situation) -descriptions Corresponding solutions are given in the found cases Problem-Description: Search for non-linear contact Search for contacting parts, that can separate

30. Storage of Successful Solved Cases The feature-Information is stored in a xml database CAD/FEM-System Analysis Case CBE-System prt xml Case Libary

31. Definition of a Problem: Two Possibilities 1. Build up features in the CAD/FEM-system 1. Build up features in the CBE-system Advantage:This method can be used with any CAD/FEM-system Advantage:All existing features are used automatically 2. Start CBE-system3. Optional insert further knowledge4. Start search 2. Start search

32. Similarity-Measurements: Method A: Find “Similar Features” Incremental ranking of a requested feature-class based on a user-weighted “Manhattan-Distance”: Example:Requested feature-class: Partn=10 Attributes + Weights Example:Number of requested results: 6

33. Similarity-Measurements: Method B: Find “Similar Feature-Structures” Exact sub-graph matching algorithm Developed by: Dennis Shasha, Courant Institute,New York University & Rosalba Giugno, Math & Computer Science, University Catania

34. Test-pattern: P containedIn(P,A) = true A Example Stress-analysis on a sheet-metal-bead Task-pattern: