More Related Content
Similar to Sesam - Efficient Engineering of Topside Structures (20)
More from João Henrique Volpini Mattos (20)
Sesam - Efficient Engineering of Topside Structures
- 1. 1
SesamTM
40 years of success
Efficient engineering of topside structures
Pål Dahlberg, Sesam Principal Sales Executive, DNV Software
10 May 2011
- 2. Efficient engineering of topside structures
Save man-hours and increase quality
by using the latest available
capabilities in concept technologies
for
- Structure modelling
- Loads & Environment modelling
- Forces, stresses, deflections
- Local models in global model
- Beam code checking
- Design iterations including redesign of
members
- Plate code checking
- Fatigue (separate presentation)
Wave or wind induced
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 2
- 3. Common challenges in design
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 3
- 4. The importance of the Sesam design loop
40-60% of engineering time
often spent in evaluation
How fast can you do it over again?
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 4
- 5. Closing the design loop – our strength
Efficient data transfer from initial modelling through
analysis, results processing and code checking
- “How long time does it take from modelling to first result?”
Efficient member code check iterations
- “What is the effect of modifying a section or code check
parameters without re-running complete analysis?”
Efficient update of model based on code check iterations
- “How long time does it take to re-generate a code
check-report based on a full re-run of model and analysis”
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 5
- 6. How can Sesam help you –
Making a model in GeniE
Structure
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 6
- 7. Structure modelling
Easy to facilitate the range from small to large and complex
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 7
- 8. GeniE uniqueness – structure modelling
Always a consistent concept model – made for frequent design changes
- Analysis models (FEM) derived from the concept model
- Beams and plates always connected, can be disconnected by use of s.el. technique
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 8
- 9. GeniE uniqueness - combined beam/shell models
Faster modelling Faster and easier re-analysis and
- Stiffeners selected from libraries optimization
- No need for calculation and evaluation of - Easy change of beam profiles from libraries
effective flange - Plate thickness changed without changing
- No lumping of loads properties for all stiffeners
- No doubts – model structure as is - Easy to change geometry, stiffener arrangement
- Always a consistent topology and other properties
- Easy to add new stiffeners or other details
More accurate results (brackets, holes etc.)
- No simplified assumptions on effective flange
and lumping of loads
- Better visual verification of model and results
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 9
- 10. GeniE uniqueness – structure modelling
Parametric modelling – define variables in script files
4.23E07 5.E07
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 10
- 11. GeniE uniqueness – structure modelling
Same system – offshore and maritime
- Fixed structures, semi’s, FPSO’s, Spar, TLP
- Tankers, containership, bulk, +++
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 11
- 13. GeniE uniqueness – structure modelling
Combine detailed models in
a global model
Beam
Plates
FE beam
FE shell
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 13
- 14. GeniE uniqueness – structure modelling
Local models
- Easy to go from global to many local models – all are based on the same concept model
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 14
- 15. How can Sesam help you –
Making a model in GeniE
Loads
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 15
- 16. Load application
Easy to include load sources from structural mass (gravity and accelerations),
equipments, manually defined loads, rule based loads (compartment loads) and
temperature loads
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 16
- 17. GeniE uniqueness – load application
Easy to define compartment loads
- Content and filling degree is enough
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 18
- 18. GeniE uniqueness – load application
Acceleration loads – multiple choices
- Constant and varying acceleration – different accelerations on various parts of structure
Lower level loads from mass Upper level loads from Rotational acceleration
x acceleration (x & z-dir) mass x acceleration (z-dir) Harmonic induced wave
motion
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 19
- 19. Topsides/modules on jackets or floaters
Topside on Jackets Topside on Floaters
- All is done inside GeniE - Opt. 1 - Integrated: Results from HydroD
- Focus of this presentation (hydrodynamic frequency or time domain
analysis) imported into GeniE
- Opt. 2 - No load transfer: Accelerations and
deflections are computed in HydroD and used as
basis for load-cases in GeniE
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 20
- 20. Floaters – frequency domain
Waves give deformations and stresses in topsides and modules
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 21
- 21. Floaters – frequency domain
Waves give deformations and stresses in topsides and modules
- These must be converted to deterministic before import to GeniE
- Our utility tool Prepost is used for this purpose
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 22
- 22. Floaters – optionally no automatic load transfer
Deformations and accelerations used to define load cases in GeniE
- Accelerations constant or centripetal (from HydroD)
- Deformations from global structural analysis (used as prescribed displacements in GeniE)
Sp1: 2mm
Sp2: 3mm
Sp3: 5mm Centripetal
Acceleration
Sp4: 2mm
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 24
- 23. Reporting
All reports can be reproduced and automatically recreated
- The report generation is scripted
- Text, html, Excel(xml), Word(xml)
The user decides the content
- Structure
- Properties
- Masses
- Loads
- Analysis (FEM) results
- Frame code check
- Plate code check
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 25
- 24. Demo-time
Make a local shell joint in a
topside model
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 26
- 25. Demo case – The model
A traditional topside model build from beams
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 27
- 26. Demo case – The loads
A combination of equipment and acceleration loads
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 28
- 27. Demo case – The results
Viewing results in plug-in component for online presentation purposes
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 29
- 28. Demo case – Deformations at selected joint
The selected joint will be converted to a shell model
- Beam model: Max deformation is 3.6 mm
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 30
- 29. Demo case – Deformations at selected joint
The joint is now a shell model part of the global model
- Combined beam and shell model: Max deformation is 3.6 mm
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 31
- 30. Demo case – Deformations at selected joint
Consistency between beam and shell elements
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 32
- 31. Demo case – The results
Viewing results in plug-in component for online presentation purposes
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 33
- 32. Demo case – speed!
Question becomes – how long time does it take
to convert the beam joint to a shell model and
re-run analysis?
- 1 day
- 1 hour
- 30 min?
- 5 min?
- 4 min?
You can start your stop watches now
- …..and not using a predefined special purpose build
script for this case….
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 34
- 33. Demo case – add details
Add brackets
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 35
- 34. How can Sesam help you –
First assessment in GeniE
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 36
- 35. Efficient engineering – typical steps
First assessment
- Forces, stresses and deflections
Code checking
- Check against prescriptive standards
Member re-design
- Evaluate the effect of modifying section
properties or code check parameters
- Often many attempts – depends on the
engineer’s experience
Design iteration
- A complete re-run of all to document the re-
design
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 37
- 36. Beam forces and stresses
Forces and stresses in 2D view as well as tabular
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 38
- 37. Beam forces and stresses
Force envelope Stress envelope
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 39
- 38. Beam deflections – 3D view
Standard 3D deformation view Using the option to compute beam
deflections without increasing number for
finite elements (absolute deflections)
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 40
- 39. Topside – 3D beam deflection view
The effect of adding cubic deformations
With cubic deflection
Linear deflection ≈ deformation view
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 41
- 40. Beam deflections – 2D view
Dy, Dz and Defl = sqrt(Dy^2 + Dz^2)
Per load-case(s)
Envelopes
Worst condition
Relative deflections
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 42
- 41. Beam deflections – tabular report
3 results are reported
- Beam length (flexible length)
- Deflection (deflections & rotations) - relative
- DELTA = Flexible beam length/Deflection
- 5-11 points may be reported per beam
- All positions or worst positions
- Per load-case or envelopes (scan)
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 43
- 42. Topside – check deflection ratio against AISC levels
AISC: Allowable deflection ratio 180, 240, 360 and scanning all load cases
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 44
- 43. Excellent design – a real case scenario
Part of a super-element analysis
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 45
- 44. Topside – all in one view
You decide what you want to see
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 46
- 45. How can Sesam help you –
Beam code checking in GeniE
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 47
- 46. Code checking in GeniE - members
Supporting
- API WSD 2002/AISC ASD 2005
- API WSD 2005/AISC ASD 2005
- API LRFD 2003/AISC LRFD 2005
- NORSOK 2004/Eurocode 3 1993
- ISO 19902 2007/Eurocode 3 1993
- DS 412/449
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 48
- 47. Easy to create capacity members
Members may be defined using complete structure or sub-sets
- Global default buckling lengths decided by the engineer
Buckling length? Buckling length?
Buckling length?
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 49
- 48. Document code check results
Graphically – complete model
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 50
- 49. Document code check results
Graphically – parts of structure only
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 51
- 50. Report code check results
Loadcases Utilisation factor
Print out using filters - All - All
- Worst - Above
- User defined - Below
Positions Members
- All - All
- Worst - Current selection
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 52
- 51. Report code check results
Example on layout
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 53
- 52. Efficient redesign of members
Redesign (“design iterations”)
- Step1: Preliminary results when
modifying section, material,
stiffener spacing or buckling length
parameters
- Note: The loads and stiffness
are not updated
- Step2: Commit changes to model
- Step3: Re-run analysis and code
check
- Reports may be automatically
re-created
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 54
- 53. Redesign – single members
Select a capacity member for redesign
Modify parameters
- Preliminary results automatically computed
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 55
- 54. Redesign – single members
Look at all details (Full Table)
- Shown with colour coding
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 56
- 55. Redesign – re-run all
The “Run All” command will
- Update structure from members
- Run analysis
- Generate code check loads (positions)
- Execute code check
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 57
- 56. Redesign – multiple members
Select capacity members for redesign
Modify parameters
- Preliminary results automatically computed
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 58
- 57. Redesign – segmented beams
Single or multiple
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 59
- 58. Redesign – segmented beams
Before and after
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 60
- 59. How can Sesam help you –
Plate code checking in GeniE
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 61
- 60. Code checking of stiffened panels
Create panels
- Panels are independent of analysis and finite
element mesh
Three different options to define panels
- Min Box finds the smallest idealised rectangular
panel possible enclosing the possibly non-
rectangular structural region
- Max Area Moment is an alternative algorithm
finding the major axis based on calculation of
area moment of inertia of the surface. This
algorithm will also work for irregular panel Min Box
shapes
- CSR Tank Default is the algorithm usually used
when doing a CSR Tank (PULS) code check
Max Area Moment
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 62
- 61. Code checking of stiffened panels – ships and offshore
Code checking according to PULS (DNV RP-C201.2)
- Linear and non-linear
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 63
- 62. Code checking of stiffened panels - offshore
Yield check of plates – based on membrane stress
- Includes a safety factor S
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 64
- 63. Code checking of stiffened panels
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 65
- 64. Code checking of stiffened panels
Demo case
- PULS non-linear on stiffened panel
- Simplified yield check of plates in stiffened panel (membrane stresses)
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 66
- 65. How can Sesam help you –
Multiple analysis in GeniE
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 67
- 66. Multiple analysis
The “master”
Multiple analysis in same project model
- E.g. Lifting, transport, in-place
- Varying parameters
- Structure
- Boundary conditions
- Load cases
Lifting Condition Transport Condition In_place Condition
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 68
- 67. Multiple analysis – graphic results
Different results at your finger-tips
- Bending moments shown
Lifting Condition
Transport Condition
In_place Condition
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 69
- 68. Multiple analysis – code check results
Different results at your finger-tips
- API WSD and default settings used in example below
Lifting Condition Transport Condition In_place Condition
Max Uf = 2.51 Max Uf = 1.85 Max Uf = 4.58
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 70
- 69. Multiple analysis
Frigg TCP2 MSF removal
Transportation
MSF: Main Support Frame
Lifting Condition
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 71
- 70. How can Sesam help you –
What is unique about us?
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 72
- 71. Our value proposition and uniqueness
An integrated and scalable life cycle solution for optimizing fixed and floating
structure design, modification and operation
Accumulates 50 years of software experience from the maritime and offshore
industry
Commercial benefits
- One vendor delivering a complete software suite for engineering design of ship and offshore
structures
- Proven track record on work done on structures
- Global presence with local sales, support and training
- Scales with your business - Flexible licensing model
- SW revenues used for further development – there are no share dividends to stock owners
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 73
- 72. Our value proposition and uniqueness
Closing the design loop by modern concept modelling and work process tools
- Quick modelling
- Local model in global model
- Scripting/parametric models
- Changes during design
- One model – many analyses
- Interaction with hydro
- Advanced hydrodynamics
- Beam/plate code checking
- Beam/plate fatigue
- Non-linear pushover
- Reporting
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 74
- 73. What’s needed to do topsides?
Full blown version of GeniE
- Including waves, current, wind and soil
- For floating structures – HydroD is needed
GeniE.lite
- Limited by model size
- 500 beams or 10.000 finite elements
- No plate code checking, waves, current, wind
and soil
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 75
- 74. “Keppel is very pleased to participate and being
consulted in the development of the redesign feature
to be launched in GeniE.”
Gao Ming, Keppel Offshore and Marine
SesamTM
25 March 2011
© Det Norske Veritas AS. All rights reserved. 76