sesam - efficient engineering of topside structures
DESCRIPTION
Análise de topsides com Sesam.TRANSCRIPT
1
Pål Dahlberg, Sesam Principal Sales Executive, DNV Software10 May 2011
SesamTM
40 years of success
Efficient engineering of topside structures
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
3
Common challenges in design
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
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?
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
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”
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
6
How can Sesam help you –Making a model in GeniE
Structure
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
7
Structure modelling Easy to facilitate the range from small to large and complex
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
9
GeniE uniqueness - combined beam/shell models Faster modelling
- Stiffeners selected from libraries- No need for calculation and evaluation of
effective flange- No lumping of loads- No doubts – model structure as is- Always a consistent topology
More accurate results- No simplified assumptions on effective flange
and lumping of loads- Better visual verification of model and results
Faster and easier re-analysis and optimization- Easy change of beam profiles from libraries- Plate thickness changed without changing
properties for all stiffeners- Easy to change geometry, stiffener arrangement
and other properties- Easy to add new stiffeners or other details
(brackets, holes etc.)
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
10
GeniE uniqueness – structure modelling Parametric modelling – define variables in script files
5.E074.23E07
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
11
GeniE uniqueness – structure modelling Same system – offshore and maritime
- Fixed structures, semi’s, FPSO’s, Spar, TLP- Tankers, containership, bulk, +++
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
12
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
13
GeniE uniqueness – structure modelling Combine detailed models in
a global model
FE shell
FE beam
Plates
Beam
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
14
GeniE uniqueness – structure modelling Local models
- Easy to go from global to many local models – all are based on the same concept model
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
15
How can Sesam help you –Making a model in GeniE
Loads
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
18
GeniE uniqueness – load application Easy to define compartment loads
- Content and filling degree is enough
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
19
GeniE uniqueness – load application Acceleration loads – multiple choices
- Constant and varying acceleration – different accelerations on various parts of structure
Lower level loads from mass x acceleration (x & z-dir)
Upper level loads from mass x acceleration (z-dir)
Rotational accelerationHarmonic induced wave
motion
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
20
Topsides/modules on jackets or floaters Topside on Jackets
- All is done inside GeniE- Focus of this presentation
Topside on Floaters- Opt. 1 - Integrated: Results from HydroD
(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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
21
Floaters – frequency domain Waves give deformations and stresses in topsides and modules
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
22
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
24
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
Sp4: 2mm
CentripetalAcceleration
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
25
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
26
Demo-time Make a local shell joint in a topside model
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
27
Demo case – The model A traditional topside model build from beams
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
28
Demo case – The loads A combination of equipment and acceleration loads
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
29
Demo case – The results Viewing results in plug-in component for online presentation purposes
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
30
Demo case – Deformations at selected joint The selected joint will be converted to a shell model
- Beam model: Max deformation is 3.6 mm
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
31
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
32
Demo case – Deformations at selected joint Consistency between beam and shell elements
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
33
Demo case – The results Viewing results in plug-in component for online presentation purposes
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
34
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….
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
35
Demo case – add details Add brackets
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
36
How can Sesam help you –First assessment in GeniE
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
37
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
38
Beam forces and stresses Forces and stresses in 2D view as well as tabular
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
39
Beam forces and stresses Force envelope Stress envelope
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
40
Beam deflections – 3D view Standard 3D deformation view Using the option to compute beam
deflections without increasing number for finite elements (absolute deflections)
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
41
Topside – 3D beam deflection view The effect of adding cubic deformations
With cubic deflection
Linear deflection ≈ deformation view
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
42
Beam deflections – 2D view Dy, Dz and Defl = sqrt(Dy^2 + Dz^2)
Per load-case(s)
Envelopes
Worst condition
Relative deflections
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
43
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)
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
44
Topside – check deflection ratio against AISC levels AISC: Allowable deflection ratio 180, 240, 360 and scanning all load cases
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
45
Excellent design – a real case scenario Part of a super-element analysis
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
46
Topside – all in one view You decide what you want to see
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
47
How can Sesam help you –Beam code checking in GeniE
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
48
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
49
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?
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
50
Document code check results
Graphically – complete model
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
51
Document code check results
Graphically – parts of structure only
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
52
Report code check results Print out using filters Loadcases
- All- Worst- User defined
Positions- All- Worst
Utilisation factor- All- Above- Below
Members- All- Current selection
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
53
Report code check results Example on layout
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
54
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
55
Redesign – single members Select a capacity member for redesign
Modify parameters- Preliminary results automatically computed
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
56
Redesign – single members Look at all details (Full Table)
- Shown with colour coding
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
57
Redesign – re-run all The “Run All” command will
- Update structure from members- Run analysis- Generate code check loads (positions)- Execute code check
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
58
Redesign – multiple members Select capacity members for redesign
Modify parameters- Preliminary results automatically computed
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
59
Redesign – segmented beams Single or multiple
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
60
Redesign – segmented beams Before and after
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
61
How can Sesam help you –Plate code checking in GeniE
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
62
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 shapes
- CSR Tank Default is the algorithm usually used when doing a CSR Tank (PULS) code check
Min Box
Max Area Moment
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
63
Code checking of stiffened panels – ships and offshore Code checking according to PULS (DNV RP-C201.2)
- Linear and non-linear
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
64
Code checking of stiffened panels - offshore Yield check of plates – based on membrane stress
- Includes a safety factor S
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
65
Code checking of stiffened panels
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
66
Code checking of stiffened panels Demo case
- PULS non-linear on stiffened panel- Simplified yield check of plates in stiffened panel (membrane stresses)
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
67
How can Sesam help you –Multiple analysis in GeniE
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
68
Multiple analysis Multiple analysis in same project
- E.g. Lifting, transport, in-place- Varying parameters
- Structure- Boundary conditions- Load cases
The “master” model
Lifting Condition Transport Condition In_place Condition
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
69
Multiple analysis – graphic results Different results at your finger-tips
- Bending moments shown
Lifting Condition
Transport Condition
In_place Condition
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
70
Multiple analysis – code check results Different results at your finger-tips
- API WSD and default settings used in example below
Lifting Condition
Max Uf = 2.51
Transport Condition
Max Uf = 1.85
In_place Condition
Max Uf = 4.58
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
71
Multiple analysis Frigg TCP2 MSF removal
Transportation
Lifting Condition
MSF: Main Support Frame
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
72
How can Sesam help you –What is unique about us?
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
73
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
74
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
75
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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
76
“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
© Det Norske Veritas AS. All rights reserved.
SesamTM
25 March 2011
77
Safeguarding life, property and the environment
www.dnv.com