1SesamTM40 years of successGeniE – Shell modelling, status and directionsOle Jan Nekstad, Sesam Product Manager, DNV Softw...
Shell modelling - statusSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved.   2
Shell modelling functionality  4 main options – they are all based on curves              Curve net interpolation        ...
Skin / loft curves  Usually works fine with all types of curves      - If not, a trick may be to rebuild the curves with ...
Use existing shell edge (model curve)  Use model curve of shell edge to ensure topological congruency  May skin/loft, co...
Curve net interpolation  Use net of interior and/or boundary curves      - Does not require trimming of curves         OK...
Internal edges  Composite curves may give internal edges          - Same issue with skin/loft          - Use global meshi...
Conclusion                                                      Preferred approach:                                 Use po...
New features for shell modelling             in GeniE v5.3-10 released April             2011SesamTM1 September 2011© Det ...
Why enhancements to existing modelling capabilities                                                        Models like thi...
Easier modelling of planar surfaces  Create closed surfaces by single click using flat region feature      - Intuitive an...
Additional options in vector selection dialog    Vector from other object        - local beam system        - plate norma...
Additional options in snap plane and divide dialogs  Plane defined by three pointsSesamTM1 September 2011© Det Norske Ver...
More features for making geometry  Scaling and offsetting of curves and surfaces makes it easier to make regular as   wel...
Meshing improvements  Separated handling of mesh and loads use less peak memory  Conditional Regenerate Mesh      - For ...
Ongoing modelling activitiesSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved.   19
Ongoing activities  64-bit version of GeniE – tentatively release date September 2011          - Performance improvements...
Ongoing activities – scheduled for release Q1/2012  Additional ways for modelling of guiding points and curves  Common r...
Ongoing activities – some examples  E.g. Different type of line representations       Guide Spline                       ...
Ongoing activities – some examples  Bezier curve and control points – shape preserving curves      - Gives the user much ...
Ongoing activities – scheduled for release Q1/2012  New DXF import using the   Rhinoceros plug-in  Poly-lines supported ...
Our biggest challenge when importing line data  Real case example – importing data from NAPA                             ...
Ongoing activities – scheduled for release Q1/2012  Mapping of one set of curves onto another   set, e.g. buttocks onto s...
Safeguarding life, property       and the environment       www.dnv.comSesamTM1 September 2011© Det Norske Veritas AS. All...
Upcoming SlideShare
Loading in …5
×

GeniE : Shell Modelling, Status and Directions

928 views

Published on

Seminar "Sesam Present & Future" in Rio on Sept 2nd 2011, presented by Ole Jan Nekstad

Published in: Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
928
On SlideShare
0
From Embeds
0
Number of Embeds
21
Actions
Shares
0
Downloads
56
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

GeniE : Shell Modelling, Status and Directions

  1. 1. 1SesamTM40 years of successGeniE – Shell modelling, status and directionsOle Jan Nekstad, Sesam Product Manager, DNV Software1 September 2011
  2. 2. Shell modelling - statusSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 2
  3. 3. Shell modelling functionality  4 main options – they are all based on curves Curve net interpolation Skin/loft Cover ExtrudeSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 3
  4. 4. Skin / loft curves  Usually works fine with all types of curves - If not, a trick may be to rebuild the curves with the same number of points  May get gaps between adjacent shells in the cross direction of the skinning direction Gap, elements don’t share the same nodes  Workaround is to use a model curve from adjacent shell in further modellingSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 4
  5. 5. Use existing shell edge (model curve)  Use model curve of shell edge to ensure topological congruency  May skin/loft, cover or net interpolate adjacent shell, as long as the model curve is used - Trimming of curves required?SesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 5
  6. 6. Curve net interpolation  Use net of interior and/or boundary curves - Does not require trimming of curves OK - Requires common intersection pointsSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 6
  7. 7. Internal edges  Composite curves may give internal edges - Same issue with skin/loft - Use global meshing rule Remove internal edgesSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 9
  8. 8. Conclusion Preferred approach: Use polycurves and curve net interpolation Need common intersection pointsSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 10
  9. 9. New features for shell modelling in GeniE v5.3-10 released April 2011SesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 11
  10. 10. Why enhancements to existing modelling capabilities Models like this can be created today. We have identified potential user efficiency gains within local modelling details and flat surface modellingSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 12
  11. 11. Easier modelling of planar surfaces  Create closed surfaces by single click using flat region feature - Intuitive and simple to use. - Bounding by existing plates, beams and guide curves - No need to split lines Insert  Plate  Flat Region Plates, beams and curves Click inside area. to position cut-plane in cut-plane Uses visible modelSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 13
  12. 12. Additional options in vector selection dialog  Vector from other object - local beam system - plate normal - 3-point plane normal, etcSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 14
  13. 13. Additional options in snap plane and divide dialogs  Plane defined by three pointsSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 15
  14. 14. More features for making geometry  Scaling and offsetting of curves and surfaces makes it easier to make regular as well as complex geometrical shapes - Scaling around a point is often used to create similar shapes for the purpose of making structure and controlling finite element mesh, Edit  Copy - Offsetting will create similar shape (line or surface) in a given distanceSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 17
  15. 15. Meshing improvements  Separated handling of mesh and loads use less peak memory  Conditional Regenerate Mesh - For large models, significant performance improvements are achieved when updating analysis models - Does not have to regenerate mesh if only properties or loads are changed. FEM file is updated instead. - Topology and mesh rule changes force new meshSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 18
  16. 16. Ongoing modelling activitiesSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 19
  17. 17. Ongoing activities  64-bit version of GeniE – tentatively release date September 2011 - Performance improvements, “unlimited” memory available – important for large models (e.g. global FPSO model) - ISO Joint Check “critical” joints, the option to compute “Ub from run” is now available - Sacs Import : Result combinations read into GeniE - Frame code checks : Results stored on HDF5 files, reducing chance of running out of virtual memorySesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 20
  18. 18. Ongoing activities – scheduled for release Q1/2012  Additional ways for modelling of guiding points and curves  Common representation of all curves using NURBS Pictures from prototype implementationSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 21
  19. 19. Ongoing activities – some examples  E.g. Different type of line representations Guide Spline Poly Curve Bezier Curve S/P Spline Curve Classic cubic G1 curve, consisting Polynomial line. Shape-preserving spline interpolation of linear and cubic Shape decided by interpolating spline segments, which control points, but no interpolates interpolation the given pointsSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 27
  20. 20. Ongoing activities – some examples  Bezier curve and control points – shape preserving curves - Gives the user much more flexibility in creating almost any curve Three control points Four control points – Four control points the middle point is used twiceSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 29
  21. 21. Ongoing activities – scheduled for release Q1/2012  New DXF import using the Rhinoceros plug-in  Poly-lines supported with new NURBS implementationsSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 30
  22. 22. Our biggest challenge when importing line data  Real case example – importing data from NAPA But often lines do not intersect All looks fine!SesamTM1 September 2011© Det Norske Veritas AS. All rights reserved.
  23. 23. Ongoing activities – scheduled for release Q1/2012  Mapping of one set of curves onto another set, e.g. buttocks onto station curves/offset table - GeniE will propose a cleaning of non-matching lines - User to decide which line to “move” to achieve matching lines Two lines are not matching All lines are matchingSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved.
  24. 24. Safeguarding life, property and the environment www.dnv.comSesamTM1 September 2011© Det Norske Veritas AS. All rights reserved. 33

×