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OrcaFlex Manual
Version 9.8a
Orcina Ltd. Daltongate Ulverston Cumbria LA12 7AJ UK Telephone: +44 (0) 1229 584742 E-mail: [email protected] Web Site: www.orcina.comw
ContentsCONTENTS
1
INTRODUCTION
11
1.1
Installing OrcaFlex
11
1.2
Running OrcaFlex
13
1.3
Parallel Processing
14
1.4
Distributed OrcaFlex
15
1.5
Orcina Licence Monitor
15
1.6
Demonstration Version
15
1.7
OrcaFlex Examples
15
1.8
Validation and QA
15
1.9
Orcina
15
1.10
References and Links
16
2
TUTORIAL
21
2.1
Getting Started
21
2.2
Building a Simple System
21
2.3
Adding a Line
21
2.4
Adjusting the View
22
2.5
Static Analysis
22
2.6
Dynamic Analysis
23
2.7
Multiple Views
23
2.8
Looking at Results
23
2.9
Getting Output
24
2.10
Input Data
24
3
USER INTERFACE
25
3.1
Introduction
25
3.1.1
Program Windows
25
3.1.2
The Model
25
3.1.3
Model States
25
3.1.4
Toolbar
27
3.1.5
Status Bar
28
3.1.6
Mouse and Keyboard Actions
28
3.2
OrcaFlex Model Files
31
3.2.1
Data Files
31
3.2.2
Text Data Files
32
3.2.3
Simulation Files
38
3.2.4
Relative Paths
39
3.3
Model Browser
39
Contents
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3.4
Libraries
43
3.4.1
Using Libraries
43
3.4.2
Building a Library
46
3.5
Menus
46
3.5.1
File Menu
46
3.5.2
Edit Menu
48
3.5.3
Model Menu
48
3.5.4
Calculation Menu
49
3.5.5
View Menu
50
3.5.6
Replay Menu
51
3.5.7
Graph Menu
51
3.5.8
Results Menu
51
3.5.9
Tools Menu
52
3.5.10 Workspace Menu
52
3.5.11 Window Menu
53
3.5.12 Help Menu
53
3.6
3D Views
53
3.6.1
View Parameters
54
3.6.2
View Control
56
3.6.3
Navigating in 3D Views
56
3.6.4
Shaded Graphics
57
3.6.5
How Objects are Drawn
58
3.6.6
Selecting Objects
60
3.6.7
Creating and Destroying Objects
60
3.6.8
Dragging Objects
60
3.6.9
Connecting Objects
60
3.6.10 Printing, Copying and Exporting Views
61
3.7
Replays
61
3.7.1
Replay Parameters
62
3.7.2
Replay Control
62
3.7.3
Custom Replays
63
3.7.4
Custom Replay Wizard
63
3.8
Data Forms
65
3.8.1
Data Fields
65
3.8.2
Data Form Editing
66
3.9
Results
67
3.9.1
Producing Results
67
3.9.2
Selecting Variables
68
3.9.3
Summary and Full Results
69
3.9.4
Statistics
69
3.9.5
Linked Statistics
69
3.9.6
Offset Tables
70
3.9.7
Line Clashing Report
70
3.9.8
Time History and XY Graphs
71
3.9.9
Range Graphs
72
3.9.10 Offset Graphs
73
3.9.11 Spectral Response Graphs
73
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Contents3.9.13 Presenting OrcaFlex Results
76
3.10
Graphs
76
3.10.1 Modifying Graphs
78
3.11
Spreadsheets
78
3.12
Text Windows
78
3.13
Workspaces
79
3.14
Comparing Data
79
3.15
Preferences
80
4
AUTOMATION
83
4.1
Introduction
83
4.2
Batch Processing
83
4.2.1
Introduction
83
4.2.2
Script Files
84
4.2.3
Script Syntax
85
4.2.4
Script Commands
85
4.2.5
Examples of setting data
88
4.2.6
Handling Script Errors
94
4.2.7
Obtaining Data Names
95
4.2.8
Automating Script Generation
95
4.3
Text Data Files
97
4.3.1
Examples of setting data
97
4.3.2
Automating Generation
103
4.4
Post-processing
105
4.4.1
Introduction
105
4.4.2
OrcaFlex Spreadsheet
105
4.4.3
Instruction Format
108
4.4.4
Pre-defined commands
110
4.4.5
Basic commands
110
4.4.6
Time History and related commands
111
4.4.7
Range Graph commands
112
4.4.8
Data commands
112
4.4.9
Instructions Wizard
113
4.4.10 Duplicate Instructions
116
5
THEORY
119
5.1
Coordinate Systems
119
5.2
Direction Conventions
120
5.3
Object Connections
121
5.4
Interpolation Methods
121
5.5
Static Analysis
123
5.5.1
Line Statics
123
5.5.2
Buoy and Vessel Statics
126
5.5.3
Vessel Multiple Statics
127
Contents
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5.6.1
Calculation Method
128
5.6.2
Ramping
130
5.7
Friction Theory
130
5.8
Spectral Response Analysis
133
5.9
Extreme Value Statistics Theory
134
5.10
Environment Theory
136
5.10.1 Buoyancy Variation with Depth
136
5.10.2 Current Theory
137
5.10.3 Seabed Theory
137
5.10.4 Seabed Non-Linear Soil Model Theory
138
5.10.5 Morison's Equation
143
5.10.6 Waves
144
5.11
Vessel Theory
151
5.11.1 Vessel Rotations
151
5.11.2 RAOs and Phases
152
5.11.3 RAO Quality Checks
154
5.11.4 Wave Drift and Sum Frequency Loads
155
5.11.5 Sea State Disturbance
160
5.11.6 Stiffness, Added Mass and Damping
161
5.11.7 Impulse Response and Convolution
164
5.11.8 Manoeuvring Load
165
5.11.9 Other Damping
166
5.11.10 Current and Wind Loads
166
5.12
Line Theory
168
5.12.1 Overview
168
5.12.2 Structural Model Details
170
5.12.3 Calculation Stages
171
5.12.4 Calculation Stage 1 Tension Forces
171
5.12.5 Calculation Stage 2 Bend Moments
172
5.12.6 Calculation Stage 3 Shear Forces
175
5.12.7 Calculation Stage 4 Torsion Moments
175
5.12.8 Calculation Stage 5 Total Load
176
5.12.9 Line End Orientation
176
5.12.10 Line Local Orientation
177
5.12.11 Treatment of Compression
177
5.12.12 Contents Flow Effects
177
5.12.13 Line Pressure Effects
179
5.12.14 Pipe Stress Calculation
180
5.12.15 Pipe Stress Matrix
181
5.12.16 Hydrodynamic and Aerodynamic Loads
182
5.12.17 Drag Chains
184
5.12.18 Line End Conditions
186
5.12.19 Interaction with the Sea Surface
186
5.12.20 Interaction with Seabed and Shapes
187
5.12.21 Clashing
187
5.13
6D Buoy Theory
189
5.13.1 Overview
189
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Contents5.13.3 Spar Buoy and Towed Fish Added Mass and Damping
192
5.13.4 Spar Buoy and Towed Fish Drag
195
5.13.5 Slam Force
197
5.13.6 Contact Forces
201
5.14
3D Buoy Theory
202
5.15
Winch Theory
203
5.16
Shape Theory
204
6
SYSTEM MODELLING: DATA AND RESULTS
207
6.1
Modelling Introduction
207
6.2
Data in Time History Files
208
6.3
Variable Data
210
6.3.1
External Functions
211
6.4
General Data
212
6.4.1
Statics
213
6.4.2
Dynamics
214
6.4.3
Integration & Time Steps
215
6.4.4
Explicit Integration
215
6.4.5
Implicit Integration
217
6.4.6
Numerical Damping
217
6.4.7
Response Calculation
218
6.4.8
Results
218
6.4.9
Post Calculation Actions
218
6.4.10 Drawing
223
6.4.11 Properties Report
223
6.5
Environment
223
6.5.1
Sea Data
224
6.5.2
Sea Density Data
225
6.5.3
Seabed Data
225
6.5.4
Wave Data
229
6.5.5
Data for Regular Waves
230
6.5.6
Data for Random Waves
230
6.5.7
Data for JONSWAP and ISSC Spectra
231
6.5.8
Data for Ochi-Hubble Spectrum
232
6.5.9
Data for Torsethaugen Spectrum
233
6.5.10 Data for Gaussian Swell Spectrum
233
6.5.11 Data for User Defined Spectrum
233
6.5.12 Data for Time History Waves
233
6.5.13 Data for User Specified Components
235
6.5.14 Data for Response Calculation
235
6.5.15 Wave Calculation
235
6.5.16 Waves Preview
237
6.5.17 Modelling Design Waves
238
6.5.18 Setting up a Random Sea
239
6.5.19 Current Data
241
6.5.20 Wind Data
243
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6.5.22 External Functions
245
6.5.23 Results
245
6.5.24 Wave Scatter Conversion
246
6.6
Solid Friction Coefficients Data
249
6.7
Vessels
251
6.7.1
Vessel Modelling Overview
252
6.7.2
Vessel Data
253
6.7.3
Vessel Types
261
6.7.4
Importing Hydrodynamic Data
287
6.7.5
Supports
296
6.7.6
Modelling Vessel Slow Drift
305
6.7.7
Vessel Response Reports
307
6.7.8
Vessel Results
308
6.8
Lines
312
6.8.1
Line Data
314
6.8.2
Line Types
329
6.8.3
Attachments
340
6.8.4
Rayleigh Damping
343
6.8.5
P-y Models
346
6.8.6
Code Checks
348
6.8.7
Line Contact
359
6.8.8
Line Results
369
6.8.9
Drag Chain Results
380
6.8.10 Flex Joint Results
380
6.8.11 Line Setup Wizard
380
6.8.12 Line Type Wizard
382
6.8.13 Chain
383
6.8.14 Rope/Wire
386
6.8.15 Line with Floats
389
6.8.16 Homogeneous Pipe
393
6.8.17 Hoses and Umbilicals
394
6.8.18 Modelling Stress Joints
396
6.8.19 Modelling Bend Restrictors
398
6.8.20 Modelling non-linear homogeneous pipes
400
6.8.21 Line Ends
402
6.8.22 Modelling Compression in Flexibles
404
6.9
6D Buoys
405
6.9.1
Wings
406
6.9.2
Common Data
407
6.9.3
Applied Loads
409
6.9.4
Wing Data
409
6.9.5
Wing Type Data
410
6.9.6
Lumped Buoy Properties
412
6.9.7
Lumped Buoy Drawing Data
413
6.9.8
Spar Buoy and Towed Fish Properties
414
6.9.9
Spar Buoy and Towed Fish Drag & Slam
416
6.9.10 Spar Buoy and Towed Fish Added Mass and Damping
417
6.9.11 Spar Buoy and Towed Fish Drawing
418
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Contents6.9.13 Other uses
421
6.9.14 External Functions
421
6.9.15 Properties Report
421
6.9.16 Results
422
6.9.17 Buoy Hydrodynamics
425
6.9.18 Hydrodynamic Properties of a Rectangular Box
426
6.9.19 Modelling a Surface-Piercing Buoy
428
6.10
3D Buoys
431
6.10.1 Data
431
6.10.2 Properties Report
432
6.10.3 Results
432
6.11
Winches
433
6.11.1 Data
434
6.11.2 Wire Properties
435
6.11.3 Control
435
6.11.4 Control by Stage
435
6.11.5 Control by Whole Simulation
436
6.11.6 Drive Unit
436
6.11.7 External Functions
437
6.11.8 Results
437
6.12
Links
438
6.12.1 Data
438
6.12.2 Results
439
6.13
Shapes
440
6.13.1 Data
441
6.13.2 Blocks
442
6.13.3 Cylinders
442
6.13.4 Curved Plates
443
6.13.5 Planes
444
6.13.6 Drawing
444
6.13.7 Results
445
6.14
All Objects Data Form
445
7
MODAL ANALYSIS
449
7.1
Data and Results
449
7.2
Theory
451
8
FATIGUE ANALYSIS
455
8.1
Introduction
455
8.2
Commands
456
8.3
Data
457
8.4
Load Cases Data for Regular Analysis
458
8.5
Load Cases Data for Rainflow Analysis
458
8.6
Load Cases Data for Spectral Analysis
459
Contents
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8.8
Components Data
461
8.9
Analysis Data
461
8.10
S-N and T-N Curves
462
8.11
Integration Parameters
463
8.12
Results
463
8.13
Automation
464
8.14
Fatigue Points
465
8.15
How Damage is Calculated
465
9
VIV ANALYSIS
469
9.1
Frequency Domain Models
469
9.1.1
SHEAR7
469
9.1.2
VIVA
476
9.2
Time Domain Models
479
9.2.1
Wake Oscillator Models
482
9.2.2
Vortex Tracking Models
485
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Introduction, Installing OrcaFlex1
INTRODUCTION
Welcome to OrcaFlex (version 9.8a), a marine dynamics program developed by Orcina for static and dynamic analysis of a wide range of offshore systems, including all types of marine risers (rigid and flexible), global analysis, moorings, installation and towed systems.
OrcaFlex provides fast and accurate analysis of catenary systems such as flexible risers and umbilical cables under wave and current loads and externally imposed motions. OrcaFlex makes extensive use of graphics to assist understanding. The program can be operated in batch mode for routine analysis work and there are also special facilities for post-processing your results including fully integrated fatigue analysis capabilities.
OrcaFlex is a fully 3D non-linear time domain finite element program capable of dealing with arbitrarily large deflections of the flexible from the initial configuration. A lumped mass element is used which greatly simplifies the mathematical formulation and allows quick and efficient development of the program to include additional force terms and constraints on the system in response to new engineering requirements.
In addition to the time domain features, modal analysis can be performed for either the whole system or for individual lines. RAOs can be calculated for any results variable using the Spectral Response Analysis feature. OrcaFlex is also used for applications in the Defence, Oceanography and Renewable energy sectors. OrcaFlex can handle multi-line systems, floating lines, line dynamics after release, etc. Inputs include ship motions, regular and random waves. Results output includes animated replay plus full graphical and numerical presentation.
If you are new to OrcaFlex then please see the tutorial and examples.
For further details of OrcaFlex and our other software, please contact Orcina or your Orcina agent.
Copyright notice
Copyright Orcina Ltd. 1987-2014. All rights reserved.
1.1 INSTALLING ORCAFLEX
Hardware RequirementsOrcaFlex can be installed and run on any computer that has:
Windows Vista, Windows 7 or Windows 8. Both 32 bit and 64 bit versions of Windows are supported.
If you are using small fonts (96dpi) the screen resolution must be at least 1024×768. If you are using large fonts (120dpi) the screen resolution must be at least 1280×1024.
However, OrcaFlex is a powerful package and to get the best results we would recommend: A 64 bit edition of Windows 7 or later.
A powerful processor with fast floating point and memory performance. This is the most important factor since OrcaFlex is a computation-intensive program and simulation run times can be long for complex models.
At least 4GB of memory. This is less important than processor performance but some aspects of OrcaFlex do perform better when more memory is available, especially on multi-core systems. If you have a multi-core system with a 64 bit version of Windows then you may benefit from fitting even more memory.
A multi-core system to take advantage of OrcaFlex's multi-threading capabilities.
As much disk space as you require to store simulation files. Simulation files vary in size, but can be hundreds of megabytes each for complex models.
A screen resolution of 1280×1024 or greater with 32 bit colour.
A DirectX 9 compatible graphics card with at least 256MB memory for the most effective use of the shaded graphics facility.
Microsoft Excel (Excel 2010, or later) in order to use the OrcaFlex automation facilities. Both 32 bit and 64 bit versions of Excel are supported although we strongly recommend the 64 bit version to avoid the severe constraints on memory usage of the 32 bit version.
Installation
To install OrcaFlex:
You will need to install from an account with administrator privileges.
If installing from disc, insert the OrcaFlex installation disc and run the Autorun.exe program on the disc (on many machines this program will run automatically when you insert the disc). Then click on 'Install OrcaFlex'.
Introduction, Installing OrcaFlex
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If you have received OrcaFlex by e-mail or from the web you will have a zip file, and possibly a number oflicence files (.lic). Extract the files from the zip file to some temporary location, and save the licence files to the same folder. Then run the extracted file Setup.exe.
You will also need to install the OrcaFlex dongle supplied by Orcina. See below for details.
For further details, including information on network and silent installation, click on Read Me on the Autorun menu or open the file Installation Guide.pdf on the disc. If you have any difficulty installing OrcaFlex please contact Orcina or your Orcina agent.
Orcina Shell Extension
When you install OrcaFlex the Orcina Shell Extension is also installed. This integrates with Windows Explorer, and associates the data and simulation file types (.dat and .sim) with OrcaFlex. You can then open an OrcaFlex file by simply double-clicking the filename in Explorer. The shell extension also provides file properties information, such as which version of OrcaFlex wrote the file and the Comments text for the model in the file.
Dongles
OrcaFlex is supplied with a dongle, a small hardware device that must be attached to the machine or to the network to which the machine is attached.
Note: The dongle is effectively your licence to run one copy (or more, if the dongle is enabled for more copies) of OrcaFlex. It is, in essence, what you have purchased or leased, and it should be treated with appropriate care and security. If you lose your dongle you cannot run OrcaFlex.
Warning: Orcina can normally resupply disks or manuals (a charge being made to cover costs) if they are lost or damaged. But we can only supply a new dongle in the case where the old dongle is returned to us.
Dongles labelled 'Hxxx' (where xxx is the dongle number) must be plugged into the machine on which OrcaFlex is run. Dongles labelled 'Nxxx' can be used in the same way as 'Hxxx' dongles, but they can also be used over a network, allowing the program to be shared by multiple users. In the latter case the dongle should be installed by your network administrator; instructions can be found in the Dongle directory on the OrcaFlex installation disc. By default, 'N' dongles can hold up to 10 OrcaFlex licences for use over a network; we can supply dongles with larger capacities on request. Dongles are usually supplied as USB devices, but parallel port dongles are still available if required.
The dongle requires a device driver to be installed on any machine to which it is attached. Windows will often do this installation automatically for you when you plug in the dongle; alternatively, you can choose to install the device driver when you install OrcaFlex.
Dongle Troubleshooting
We supply, with OrcaFlex, a dongle utility program called OrcaDongle. If OrcaFlex cannot find the dongle then this program may be used to check that the dongle is working correctly and has the expected number of licences. For details see the OrcaDongle help file.
The OrcaDongle program is included on the OrcaFlex installation disc, and you may choose to install it from the Autorun menu in the same way as OrcaFlex. It is also available for download from www.orcina.com/Support/Dongle.
Users of network dongles may find the Orcina Licence Monitor to be useful. This application monitors the OrcaFlex licences claimed on a network at any time and reports which machines and users are claiming licences for the various Orcina programs.
Diagnostics
If OrcaFlex fails to start, with the error that it can't obtain a licence, then please check the following.
If you are using a network dongle, are all the licences in use? The Orcina Licence Monitor may be of use in determining this. If they are, you will need to wait until a licence becomes free before you can run OrcaFlex. If you are using a local dongle, is it plugged into your machine? If so, is the dongle device driver installed? You
can check this by running OrcaDongle. If the driver is not present, you can follow the link on our website to download the latest driver software from the dongle manufacturer.
Does the dongle you are using have an OrcaFlex licence on it? Again, you can check this with OrcaDongle. Do you have a licence file for the dongle you wish to access? This file will be named Nxxx.lic or Hxxx.lic (where
xxx is the dongle number) and will be in the OrcaFlex installation folder. If not, then you should be able to copy the required file(s) from the root level of the OrcaFlex installation disc into the installation folder.
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Introduction, Running OrcaFlex If none of these help, then please contact us at Orcina with a description of the problem. Ideally, please also email to us the diagnostics file named OrcLog.txt which OrcaFlex will have written on failing to find a licence. This file can be found in the folder "%appdata%\Orcina\OrcaFlex". To open this folder, select Start menu | Run… (or Windows key and 'R') and enter the text between the quotes (including the % characters).1.2 RUNNING ORCAFLEX
A shortcut to run OrcaFlex is set up on the Start menu when you install OrcaFlex (see Start\Programs\Orcina Software\ or the All Apps screen, "Orcina Software" group, depending on your version of Windows).
This shortcut passes no parameters to OrcaFlex so it gives the default start-up behaviour; see below. If this is not suitable you can configure the start-up behaviour using command-line parameters, for example by setting up your own shortcuts with particular parameter settings.
Default Start-up
OrcaFlex has two basic modules: full OrcaFlex and statics-only OrcaFlex. A full OrcaFlex licence is needed for dynamic analysis.
When you run OrcaFlex it looks for an Orcina dongle from which it can claim an OrcaFlex licence (either a full licence or a statics-only licence). By default, it first looks for a licence on a local dongle (i.e. one in local mode and connected to the local machine) and if none is found then it looks for a licence on a network dongle (i.e. one in network mode and accessed via a licence manager over the network). This default behaviour can be changed by command-line parameters.
If OrcaFlex finds a network dongle and there is a choice of which licences to claim from it, then OrcaFlex displays a
Choose Modules dialog to ask you which modules you want to claim. This helps you share the licences with other
users of that network dongle. For example if the network dongle contains both a full licence and a statics-only licence then you can choose to use the statics-only licence, if that is all you need, so that the full licence is left free for others to use when you do not need it yourself. The Choose Modules dialog can be suppressed using command-line parameters.
Command Line Parameters
OrcaFlex can accept various parameters on the command line to modify the way it starts up. The syntax is: OrcaFlex.exe Filename Option1 Option2 … etc.
Filename is optional. If present it should be the name of an OrcaFlex data file (.dat or .yml) or simulation file (.sim). After starting up OrcaFlex will automatically open that file.
Option1, Option2 etc. are optional parameters that allow you configure the start-up behaviour. They can be any of the following switches. For the first character of an option switch, the hyphen character '-' can be used as an alternative to the '/' character.
Dongle Search switches
By default the program searches first for a licence on a local dongle and then for a licence on a network dongle. The following switches allow you to modify this default behaviour.
/LocalDongle Only search for licences on a local dongle. No search will be made for network dongles.
/NetworkDongle Only search for licences on a network dongle. Any local dongle will be ignored. This can be useful if you have a local dongle but want to use a network dongle that has licences for more modules.
Module Choice switch
This switch is only relevant if the dongle found is a network dongle and there is a choice of licences to claim from that dongle. You can specify your choice using the following command line switch:
/DisableDynamics Choose the statics-only basic licence. This is sometimes useful when using a network dongle since it allows you to leave full licences free for other users when you only need a statics-only licence.
If you do not specify all the choices then the program displays the Choose Modules dialog to ask for your remaining choices. You can suppress this dialog using the following switch.
/DisableInteractiveStartup Do not display the Choose Modules dialog. The program behaves the same as if the user clicks OK on that dialog without changing any module choices.
Batch Calculation switches
These switches allow you to instruct OrcaFlex to start a batch calculation as soon as the program has loaded. The following switches are available:
Introduction, Parallel Processing
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/Batch Start a batch calculation as soon as the program has loaded. The batch calculation will contain all the files specified on the command line (you can have more than one) in the order in which they are specified. You can use relative paths which will be relative to the working directory. /CloseAfterBatch Instructs the program to close once the batch is complete.
/BatchAnalysisStatics, /BatchAnalysisDynamics specify what type of analysis to perform to the specified files. If these parameters are missing then the program defaults to dynamic analysis.
/FileList instructs the program that any text files specified on the command line contain a list of files to include in the batch calculation. The command line can contain more than one file list. Text files within the file list will be treated as batch script files.
Note that the batch calculation switches are provided for backwards compatibility. We recommend that automation of analysis be carried out using Distributed OrcaFlex or one of the programming interfaces.
Process Priority switches
These switches determine the processing priority of OrcaFlex. The available switches are /RealtimePriority,
/HighPriority, /AboveNormalPriority, /NormalPriority, /BelowNormalPriority, /LowPriority.
ThickLines switch
The /ThickLines switch allows you to specify a minimum thickness for lines drawn on OrcaFlex 3D View windows. For example using the switch /ThickLines=5 forces OrcaFlex to draw all lines at a thickness of at least 5. If no value is specified (i.e. the switch is /ThickLines) then the minimum thickness is taken to be 2.
This switch has been added to make OrcaFlex 3D Views clearer when projected onto a large screen.
ThreadCount switch
The /ThreadCount switch allows you to set the number of execution threads used by OrcaFlex for parallel processing. For example /ThreadCount=1 forces OrcaFlex to use a single execution thread which has the effect of disabling parallel processing.
32 and 64 bit OrcaFlex
The installation package copies both 32 and 64 bit versions of the executables, even on a 32 bit system. On a 32 bit system, the shortcuts and file associations are configured to execute the 32 bit version. On a 64 bit system, the shortcuts and file associations are configured to execute the 64 bit version. If you wish to create a shortcut to the 32 bit version on a 64 bit system, you will need to set it up yourself – the installation program does not do so. Conversely, the 64 bit executable will not run on a 32 bit system. The 32 bit executable is named OrcaFlex.exe and the 64 bit executable is named OrcaFlex64.exe.
The 64 bit version runs slightly quicker than the 32 bit version. However, the main benefit of 64 bits is that this version can access more memory than the 32 bit version. This is especially significant for machines with a very large number of processors.
All OrcaFlex automation capabilities are fully supported for both 32 and 64 bit. The OrcaFlex DLL, OrcFxAPI, is available in both 32 and 64 bit versions. The different versions of the DLL are both named OrcFxAPI.dll. The installation program installs binary files (.dll, .lib) to <InstallationDir>\OrcFxAPI\Win32 and <InstallationDir>\OrcFxAPI\Win64 respectively. Versions of OrcaFlex prior to 9.6 also installed OrcFxAPI.dll to the Windows system directory; this is no longer the case. Please refer to the OrcFxAPI help file for details of how to link to OrcFxAPI.dll.
1.3 PARALLEL PROCESSING
Machines with multiple processors or processors with multiple cores are becoming increasingly common. OrcaFlex can make good use of the additional processing capacity afforded by such machines. For up to date information on hardware choice for OrcaFlex please refer to www.orcina.com/Support/Benchmark.
OrcaFlex performs the calculations of the model's Line objects in parallel. This means that, interactively at least, performance is only improved for models with more than one Line object. However, for models with more than one Line performance is significantly improved.
Batch processing, fatigue analysis and OrcaFlex spreadsheet post-processing tasks process jobs and load cases concurrently, using all available processing resources.
Thread count
OrcaFlex manages a number of execution threads to perform the parallel calculations. The number of these threads (the thread count) defaults to the number of logical processors available on your machine, as reported by the operating system. This default will work well for most cases. Should you wish to change it you can use the Tools | Set Thread Count menu item. The thread count can also be controlled by a command line switch.
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Introduction, Distributed OrcaFlex1.4 DISTRIBUTED ORCAFLEX
Distributed OrcaFlex is a suite of programs that enables a collection of networked, OrcaFlex licensed computers to run OrcaFlex jobs, transparently, using spare processor time. For more information about Distributed OrcaFlex please refer to www.orcina.com/Support/DistributedOrcaFlex. Distributed OrcaFlex can be downloaded from this address.
OrcaFlex can also make use of machines with multiple processors using parallel processing technology.
1.5 ORCINA LICENCE MONITOR
The Orcina Licence Monitor (OLM) is a service that monitors the current number of OrcaFlex licences claimed on a network in real time. Other programs that use the OrcaFlex programming interface (OrcFxAPI) such as Distributed OrcaFlex and the OrcaFlex spreadsheet are also monitored. You can obtain information on each licence claimed that includes:
Network information: the computer name, network address and the user name.
Licence information: the dongle name, the dongle type (network or local) and the time the licence was claimed. Program information: which modules are being used, the version, and the location of the program which has
claimed the licence. Usually this is the OrcaFlex executable, but it can also be, for example, Excel when the licence is claimed by the OrcaFlex spreadsheet.
OLM can be downloaded from www.orcina.com/Support/OrcinaLicenceMonitor.
1.6 DEMONSTRATION VERSION
For an overview of OrcaFlex, see the Introduction topic and the tutorial.
The demonstration version of OrcaFlex has some facilities disabled – you cannot calculate statics or run simulation, and you cannot save files, print, export or copy to the clipboard. Otherwise the demonstration version is just like the full version, so it allows you to see exactly how the program works.
In particular the demonstration version allows you to open any prepared OrcaFlex data or simulation file. If you open a simulation file then you can then examine the results, see replays of the motion etc. There are numerous example files provided on the demonstration disc. These example files are also available from www.orcina.com/SoftwareProducts/OrcaFlex/Examples.
If you have the full version of OrcaFlex then you can use the demonstration version to show your customers your OrcaFlex models and results for their system. To do this, give them the demonstration version and copies of your OrcaFlex simulation files. The demonstration version can be downloaded from www.orcina.com/SoftwareProducts/OrcaFlex/Demo.
1.7 ORCAFLEX EXAMPLES
OrcaFlex is supplied with an examples disc containing a comprehensive collection of example files. These examples can also be found at www.orcina.com/SoftwareProducts/OrcaFlex/Examples.
1.8 VALIDATION AND QA
The OrcaFlex validation documents are available from www.orcina.com/SoftwareProducts/OrcaFlex/Validation.
1.9 ORCINA
Orcina is a creative engineering software and consultancy company staffed by mechanical engineers, naval architects, mathematicians and software engineers with long experience in such demanding environments as the offshore, marine and nuclear industries. As well as developing engineering software, we offer a wide range of analysis and design services with particular strength in dynamics, hydrodynamics, fluid mechanics and mathematical modelling. Contact Details Orcina Ltd. Daltongate Ulverston Cumbria LA12 7AJ UK
Introduction, References and Links
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Telephone: +44 (0) 1229 584742E-mail: [email protected] Web Site: www.orcina.com
Orcina Agents
We have agents in many parts of the world. For details please refer to www.orcina.com/ContactOrcina.
1.10 REFERENCES AND LINKS
ReferencesAPI, 1993. API RP 2A-WSD, Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms – Working Stress Design. American Petroleum Institute.
API, 2000. API RP 2A-WSD, Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms – Working Stress Design. American Petroleum Institute.
API, 1998. API RP 2RD, Design of Risers for Floating Production Systems and Tension-Leg Platforms. American Petroleum Institute.
API, 2005. API RP 2SK, Design and Analysis of Stationkeeping Systems for Floating Structures. American Petroleum Institute.
API, 2009. API RP 1111, Design, Construction, Operation, and Maintenance of Offshore Hydrocarbon Pipelines (Limit State Design). American Petroleum Institute.
API. Comparison of Analyses of Marine Drilling Risers. API Bulletin. 2J.
Aranha J A P, 1994. A formula for wave drift damping in the drift of a floating body. J. Fluid Mech. 275, 147-155. Aubeny C, Biscontin G and Zhang J, 2006. Seafloor interaction with steel catenary risers. Offshore Technology Research Center (Texas A&M University) Final Project Report (http://www.mms.gov/tarprojects/510.htm).
Aubeny C, Gaudin C and Randolph M, 2008. Cyclic Tests of Model Pipe in Kaolin. OTC 19494, 2008.
Barltrop N D P and Adams A J, 1991. Dynamics of fixed marine structures. Butterworth Heinemann for MTD. 3rd Edition.
Bellanger M, 1989. Digital Processing of Signals. Wiley.
Blevins R D, 2005. Forces on and Stability of a Cylinder in a Wake. J. OMAE, 127, 39-45.
Bridge C, Laver K, Clukey E, Evans T, 2004. Steel Catenary Riser Touchdown Point Vertical Interaction Models. OTC 16628, 2004.
BSI, 2004. PD 8010, Code of practice for pipelines, Part 2: Subsea pipelines. British Standards.
Bureau Veritas, 2002. NR 493 R02 E, Classification of Mooring Systems for Permanent Offshore Units.
Carter D J T, 1982. Prediction of Wave height and Period for a Constant Wind Velocity Using the JONSWAP Results, Ocean Engineering, 9, no. 1, 17-33.
Casarella M J and Parsons M, 1970. Cable Systems Under Hydrodynamic Loading. Marine Technology Society Journal
4, No. 4, 27-44.
Chapman D A, 1984. Towed Cable Behaviour During Ship Turning Manoeuvres. Ocean Engineering. 11, No. 4.
Chung J and Hulbert G M, 1993. A time integration algorithm for structural dynamics with improved numerical dissipation: The generalized-α method. ASME Journal of Applied Mechanics. 60, 371-375.
CMPT, 1998. Floating structures: A guide for design and analysis. Edited by Barltrop N D P. Centre for Marine and Petroleum Technology publication 101/98, Oilfield Publications Limited.
Coles S, 2001. An Introduction to Statistical Modelling of Extreme Values. Springer.
Cummins W E, 1962. The impulse response function and ship motions. Schiffstechnik, 9, 101-109.
Dean R G, 1965. Stream function representation of non-linear ocean waves. J. Geophys. Res., 70, 4561-4572. Dirlik T, 1985. Application of computers in Fatigue Analysis. PhD Thesis University of Warwick.
DNV-OS-E301, Position Mooring, October 2010.
DNV-OS-F101, Submarine Pipeline Systems, August 2012. DNV-OS-F201, Dynamic Risers, October 2010.
DNV-RP-C205, Environmental Conditions and Environmental Loads, October 2010. DNV-RP-H103, Modelling and Analysis of Marine Operations, April 2011.
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Introduction, References and Links ESDU 80025. Mean forces, pressures and flow field velocities for circular cylindrical structures: Single cylinder with two-dimensional flow. ESDU 80025 ESDU International, London.Falco M, Fossati F and Resta F, 1999. On the vortex induced vibration of submarine cables: Design optimization of wrapped cables for controlling vibrations. 3rd International Symposium on Cable Dynamics, Trondheim, Norway.
Faltinsen O M, 1990. Sea loads on ships and offshore structures. Cambridge University Press. Fenton J D, 1979. A high-order cnoidal wave theory. J. Fluid Mech. 94, 129-161.
Fenton J D, 1985. A fifth-order Stokes theory for steady waves. J. Waterway, Port, Coastal & Ocean Eng. ASCE. 111, 216-234.
Fenton J D, 1990. Non-linear wave theories. Chapter in "The Sea – Volume 9: Ocean Engineering Science", edited by B. Le MeHaute and D. M. Hanes. Wiley: New York. 3-25.
Fenton J D, 1995. Personal communication – pre-print of chapter in forthcoming book on cnoidal wave theory. Gregory R W and Paidoussis M P, 1996. Unstable oscillation of tubular cantilevers conveying fluid: Part 1:Theory. Proc. R. Soc. 293 Series A, 512-527.
Hartnup G C, Airey R G and Fraser J M, 1987. Model Basin Testing of Flexible Marine Risers. OMAE Houston. Hoerner S F 1965. Fluid Dynamic Drag, Published by the author at Hoerner Fluid Dynamics, NJ 08723, USA. Huse E, 1993. Interaction in Deep-Sea Riser Arrays. OTC 7237, 1993.
Isherwood R M, 1987. A Revised Parameterisation of the JONSWAP Spectrum. Applied Ocean Research, 9, No. 1 (January), 47-50.
Iwan W D, 1981. The vortex-induced oscillation of non-uniform structural systems. Journal of Sound and Vibration,
79, 291-301.
Iwan W D and Blevins R D, 1974. A Model for Vortex Induced Oscillation of Structures. Journal of Applied Mechanics, September 1974, 581-586.
Kotik J and Mangulis V, 1962. On the Kramers-Kronig relations for ship motions. Int. Shipbuilding Progress, 9, No. 97, 361-368.
Lamb H, 1932. Hydrodynamics. 6th Edition.Cambridge University Press.
Larsen C M, 1991. Flexible Riser Analysis – Comparison of Results from Computer Programs. Marine Structures, Elsevier Applied Science.
Longuet-Higgins M S, 1983. On the joint distribution of wave periods and amplitudes in a random wave field. Proceedings Royal Society London, Series A, Mathematical and Physical Sciences.389, 241-258.
Maddox S J, 1998. Fatigue strength of welded structures. Woodhead Publishing Ltd, ISBN 1 85573 013 8.
Malenica S et al, 1995. Wave and current forces on a vertical cylinder free to surge and sway. Applied Ocean Research, 17, 79-90.
Molin B, 1994. Second-order hydrodynamics applied to moored structures. A state-of-the-art survey. Ship Technology Research. 41, 59-84.
Morison J R, O'Brien M D, Johnson J W, and Schaaf S A, 1950. The force exerted by surface waves on piles. Petrol Trans AIME. 189.
Mueller H F, 1968. Hydrodynamic forces and moments of streamlined bodies of revolution at large incidence. Schiffstechnik. 15, 99-104.
Newman J N. 1974. Second-order, slowly-varying forces on vessels in irregular waves. Proc Int Symp Dynamics of Marine Vehicles and Structures in Waves, Ed. Bishop RED and Price WG, Mech Eng Publications Ltd, London.
Newman J N, 1977. Marine Hydrodynamics, MIT Press.
NDP, 1995. Regulations relating to loadbearing structures in the petroleum activities. Norwegian Petroleum Directorate.
Ochi M K and Hubble E N, 1976. Six-parameter wave spectra, Proc 15th Coastal Engineering Conference, 301-328. Ochi M K, 1973. On Prediction of Extreme Values, J. Ship Research, 17, No. 1, 29-37.
Ochi M K, 1998. Ocean Waves: The Stochastic Approach, Cambridge University Press.
Oil Companies International Marine Forum, 1994. Prediction of Wind and Current Loads on VLCCs, 2nd edition,
Witherby & Co., London.
Paidoussis M P, 1970. Dynamics of tubular cantilevers conveying fluid. J. Mechanical Engineering Science, 12, No 2, 85-103.
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Paidoussis M P and Lathier B E, 1976. Dynamics of Timoshenko beams conveying fluid. J. Mechanical Engineering Science, 18, No 4, 210-220.Palmer A C and Baldry J A S, 1974. Lateral buckling of axially constrained pipes. J. Petroleum Technology, Nov 1974, 1283-1284.
Pode L, 1951. Tables for Computing the Equilibrium Configuration of a Flexible Cable in a Uniform Stream. DTMB Report. 687.
Principles of Naval Architecture. Revised edition, edited by J P Comstock, 1967. Society of Naval Architects and Marine Engineers, New York.
Puech A, 1984. The Use of Anchors in Offshore Petroleum Operations. Editions Technip.
Randolph M and Quiggin P, 2009. Non-linear hysteretic seabed model for catenary pipeline contact. OMAE paper 79259, 2009 (www.orcina.com/Resources/Papers/OMAE2009-79259.pdf).
Rawson and Tupper, 1984. Basic Ship Theory 3rd ed, 2: Ship Dynamics and Design, 482. Longman Scientific & Technical (Harlow).
Rienecker M M and Fenton J D, 1981. A Fourier approximation method for steady water waves. J. Fluid Mech. 104, 119-137.
Roark R J, 1965. Formulas for Stress and Strain. 4th edition McGraw-Hill.
Sarpkaya T, Shoaff R L, 1979. Inviscid Model of Two-Dimensional Vortex Shedding by a Circular Cylinder. Article No. 79-0281R, AIAA Journal,17, no. 11, 1193-1200.
Sarpkaya T, Shoaff R L, 1979. A discrete-vortex analysis of flow about stationary and transversely oscillating circular cylinders. Report no. NPS-69SL79011, Naval Postgraduate School, Monterey, California.
Rychlik I, 1987. A new definition of the rainflow cycle counting method. Int. J. Fatigue 9, No 2, 119-121. Skjelbreia L, Hendrickson J, 1961. Fifth order gravity wave theory. Proc. 7th Conf. Coastal Eng. 184-196.
Sobey R J, Goodwin P, Thieke R J and Westberg R J, 1987. Wave theories. J. Waterway, Port, Coastal & Ocean Eng. ASCE 113, 565-587.
Sparks C P, 1980. Le comportement mecanique des risers influence des principaux parametres. Revue de l'Institut Francais du Petrol, 35, no. 5, 811.
Sparks C P, 1984. The influence of tension, pressure and weight on pipe and riser deformations and stresses. J. Energy Resources Technology, 106, Issue 1, 46-54.
Standing RG, Brendling WJ, Wilson D, 1987. Recent Developments in the Analysis of Wave Drift Forces, Low-Frequency Damping and Response. OTC paper 5456, 1987.
Tan Z, Quiggin P, Sheldrake T, 2007. Time domain simulation of the 3D bending hysteresis behaviour of an unbonded flexible riser. OMAE paper 29315, 2007 (www.orcina.com/Resources/Papers/OMAE2007-29315.pdf). Taylor R and Valent P, 1984. Design Guide for Drag Embedment Anchors, Naval Civil Engineering Laboratory (USA), TN No N-1688.
Torsethaugen K and Haver S, 2004. Simplified double peak spectral model for ocean waves, Paper No. 2004-JSC-193, ISOPE 2004 Touson, France.
Thwaites, 1960. Incompressible Aerodynamics, Oxford, 399-401. Timoshenko S,1955. Vibration Problems in Engineering, van Nostrand.
Triantafyllou M S, Yue D K P and Tein D Y S, 1994. Damping of moored floating structures. OTC 7489, Houston, 215-224.
Tucker et al, 1984. Applied Ocean Research, 6, No 2.
Tucker M J, 1991. Waves in Ocean Engineering. Ellis Horwood Ltd. (Chichester).
Wichers J E W, 1979. Slowly oscillating mooring forces in single point mooring systems. BOSS79 (Second International Conference on Behaviour of Offshore Structures).
Wichers J E W, 1988. A Simulation Model for a Single Point Moored Tanker. Delft University Thesis.
Wu M, Saint-Marcoux J-F, Blevins R D, Quiggin P P, 2008. Paper No. ISOPE-2008-MWU10. ISOPE Conference 2008, Vancouver, Canada. (www.orcina.com/Resources/Papers/ISOPE2008-MWU-10.pdf)
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Introduction, References and LinksSuppliers of frequency domain VIV software
SHEAR7
AMOG Consulting Inc.
770 South Post Oak Lane, Suite 505 Houston, TX 77056 USA Attention: Dr. H. Marcollo Tel: +1 713 255 0020 Email: [email protected] VIVA JD Marine
11777 Katy Freeway, Suite 434 South Houston, TX 77079
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Tel: +1 281 531 0888 Email: [email protected]
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Tutorial, Getting Started2
TUTORIAL
2.1 GETTING STARTED
This short tutorial gives you a very quick run through the model building and results presentation features of OrcaFlex.
On completion of the tutorial we suggest that you also look through the pre-run examples – see Example Files. On starting up OrcaFlex, you are presented with a 3D view showing just a blue line representing the sea surface and a brown line representing the seabed. At the top of the screen are menus, a tool bar and a status bar arranged in the manner common to most Windows software. As usual in Windows software, nearly all actions can be done in several ways: here, to avoid confusion, we will usually only refer to one way of doing the action we want, generally using the mouse.
Figure: The OrcaFlex main window
2.2 BUILDING A SIMPLE SYSTEM
To start with, we will build a simple system consisting of one line and one vessel only.
Using the mouse, click on the new vessel button on the toolbar. The cursor changes from the usual pointer to a crosshair cursor to show that you have now selected a new object and OrcaFlex is waiting for you to decide where to place it. Place the cursor anywhere on the screen and click the mouse button. A "ship" shape appears on screen, positioned at the sea surface, and the cursor reverts to the pointer shape. To select the vessel, move the cursor close to the vessel and click the mouse button – the message box (near the top of the 3D view) will confirm when the vessel has been selected. Now press and hold down the mouse button and move the mouse around. The vessel follows the mouse horizontally, but remains at the sea surface. (To alter vessel vertical position, or other details, select the vessel with the mouse, then double click to open the Vessel data window.)
2.3 ADDING A LINE
Now add a line. Using the mouse, click on the new line button . The crosshair cursor reappears – move the mouse to a point just to the right of the vessel and click. The line appears as a catenary loop at the mouse position. Move the mouse to a point close to the left-hand end of the line, press and hold down the mouse button and move the mouse around. The end of the line moves around following the mouse, and the line is redrawn at each position. Release the mouse button, move to the right-hand end, click and drag. This time the right-hand end of the line is dragged around. In this way, you can put the ends of the lines roughly where you want them. (Final positioning to exact locations has to be done by typing in the appropriate numbers – select the line with the mouse and double click to bring up the line data form.)
Move the line ends until the left-hand end of the line is close to the bow of the ship, the right-hand end lies above the water and the line hangs down into the water.
At this point, the line has a default set of properties and both ends are at fixed positions relative to the Global origin. For the moment we will leave the line properties (length, mass, etc.) at their default values, but we will connect the left-hand end to the ship. Do this as follows:
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1. Click on the line near the left-hand end, to select that end of the line; make sure you have selected the line, notthe vessel or the sea. The message box at the left-hand end of the status bar tells you what is currently selected. If you have selected the wrong thing, try again. (Note that you don't have to click at the end of the line in order to select it – anywhere in the left-hand half of the line will select the left-hand end. As a rule, it is better to choose a point well away from any other object when selecting something with the mouse.)
2. Release the mouse and move it to the vessel, hold down the CTRL key and click. The message box will confirm the connection and, to indicate the connection, the triangle at the end of the line will now be the same colour as the vessel.
Now select the vessel again and drag it around with the mouse. The left-hand end of the line now moves with the vessel. Leave the vessel positioned roughly as before with the line in a slack catenary.
2.4 ADJUSTING THE VIEW
The default view of the system is an elevation of the global X-Z plane – you are looking horizontally along the positive Y axis. The view direction (the direction you are looking) is shown in the Window Title bar in azimuth/elevation form (azimuth=270; elevation=0). You can move your view point up, down, right or left, and you can zoom in or out, using the view control buttons near the top left corner of the window. Click on each of the top 3 buttons in turn: then click again with the SHIFT key held down. The SHIFT key reverses the action of the button. If you want to move the view centre without rotating, use the scroll bars at the bottom and right edges of the window. By judicious use of the buttons and scroll bars you should be able to find any view you like.
Alternatively, you can alter the view with the mouse. Hold down the ALT key and left mouse button and drag. A rectangle on screen shows the area which will be zoomed to fill the window when the mouse button is released.
SHIFT+ALT+left mouse button zooms out – the existing view shrinks to fit in the rectangle.
Warning: OrcaFlex will allow you to look up at the model from underneath, effectively from under the seabed! Because the view is isometric and all lines are visible, it is not always apparent that this has occurred. When this has happened, the elevation angle is shown as negative in the title bar. There are three shortcut keys which are particularly useful for controlling the view. For example CTRL+P gives a plan view from above; CTRL+E gives an elevation; CTRL+Q rotates the view through 90° about the vertical axis. (CTRL+P
and CTRL+E leave the view azimuth unchanged.)
Now click the button on the 3D View to bring up the Edit View Parameters form. This gives a more precise way of controlling the view and is particularly useful if you want to arrange exactly the same view of 2 different models – say 2 alternative configurations for a particular riser system. Edit the view parameters if you wish by positioning the cursor in the appropriate box and editing as required.
If you should accidentally lose the model completely from view (perhaps by zooming in too close, or moving the view centre too far) there are a number of ways of retrieving it:
Press CTRL+T or right click in the view window and select Reset to Default View.
Press the Reset button on the Edit View Parameters form. This also resets back to the default view. Zoom out repeatedly until the model reappears.
Close the 3D View and add a new one (use the Window|Add 3D View menu item). The new window will have the default view centre and view size.
2.5 STATIC ANALYSIS
Note: If you are running the demonstration version of OrcaFlex then this facility is not available.
To run a static analysis of the system, click on the calculate statics button . The message box reports which line is being analysed and how many iterations have occurred. When the analysis is finished (almost instantly for this simple system) the Program State message in the centre of the Status Bar changes to read "Statics Complete", and the Static Analysis button changes to light grey to indicate that this command is no longer available. The appearance of the line will have changed a little. When editing the model, OrcaFlex uses a quick approximation to a catenary shape for general guidance only, and this shape is replaced with the true catenary shape when static analysis has been carried out. (See Static Analysis for more details).
We can now examine the results of the static analysis by clicking on the Results button . This opens a Results Selection window.
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Tutorial, Dynamic Analysis Results in numerical and graphical form, with various further choices which determine what the table or graphwill contain.
Results for all objects or one selected object.
Ignore the graph options for the moment, select Summary Results and All Objects, then click Table. A summary of the static analysis results is then displayed in spreadsheet form. Results for different objects are presented in different sheets. To view more static analysis results repeat this process: click on the Results button and select as before.
2.6 DYNAMIC ANALYSIS
We are now ready to run the simulation. If you are running the demonstration version of OrcaFlex then you cannot do this, but instead you can load up the results of a pre-run simulation – see Examples.
Click the Run Dynamic Simulation button . As the simulation progresses, the status bar reports current simulation time and expected (real) time to finish the analysis, and the 3D view shows the motions of the system as the wave passes through.
Click the Start Replay button . An animated replay of the simulation is shown in the 3D view window. Use the view control keys and mouse as before to change the view. The default Replay Period is Whole Simulation. This means that you see the simulation start from still water, the wave building and with it the motions of the system. Simulation time is shown in the Status bar, top left. Negative time means the wave is still building up from still water to full amplitude. At the end of the simulation the replay begins again.
The replay consists of a series of "frames" at equal intervals of time. Just as you can "zoom" in and out in space for a closer view, so OrcaFlex lets you "zoom" in and out in time. Click on the Replay Parameters button , edit Interval to 0.5s and click OK. The animated replay is now much jerkier than before because fewer frames are being shown. Now click again on Replay Parameters, set Replay Period to Latest Wave and click on the Continuous box to deselect. The replay period shown is at the end of the simulation and has duration of a single wave period. At the end of the wave period the replay pauses, then begins again.
Now click on the Replay Step button to pause the replay. Clicking repeatedly on this button steps through the replay one frame at a time – a very useful facility for examining a particular part of the motion in detail. Click with
the SHIFT key held down to step backwards.
You can then restart the animation by clicking on 'Start Replay' as before. To slow down or speed up the replay, click on Replay Parameters and adjust the speed. Alternatively use the shortcuts CTRL+F and SHIFT+CTRL+F to make the replay faster or slower respectively.
To exit from replay mode click on the Stop Replay button .
2.7 MULTIPLE VIEWS
You can add another view of the system if you wish by clicking on the View button . Click again to add a third view, etc. Each view can be manipulated independently to give, say, simultaneous plan and elevation views. To make all views replay together, click on Replay Control and check the All Views box. To remove an unwanted view simply close its view window. To rearrange the screen and make best use of the space, click Window and choose Tile
Vertical (F4) or Tile Horizontal (SHIFT+F4). Alternatively, you can minimise windows so that they appear as small icons on the background, or you can re-size them or move them around manually with the mouse. These are standard Windows operations which may be useful if you want to tidy up the screen without having to close a window down completely.
2.8 LOOKING AT RESULTS
Now click on the Results button . This opens a Results Selection window. You are offered the following choices:
Results as Tables or Graphs, with various further choices which determine what the table or graph will contain. Results for all objects or one selected object.
Select Time History for any line, then select Effective Tension at End A and click the Graph button. The graph appears in a new window. You can call up time histories of a wide range of parameters for most objects. For lines,
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show maximum, mean and minimum values of the variable plotted against position along the line. Detailed numerical results are available by selecting Summary Results, Full Results, Statistics and Linked Statistics.Time history and range graph results are also available in numerical form – select the variable you want and press the Values button. The results can be exported as Excel compatible spreadsheets for further processing as required. Further numerical results are available in tabular form by selecting Summary Results, Full Results, Statistics and Linked Statistics.
Results Post-Processing
Extra post-processing facilities are available through Excel spreadsheets.
2.9 GETTING OUTPUT
You can get printed copies of data, results tables, system views and results graphs by means of the File | Print menu, or by clicking Print on the popup menu. Output can also be transferred into other applications, either using copy and paste via the clipboard or else by exporting to a file, again using the popup menu.
Note: Printing and export facilities are not available in the demonstration version of OrcaFlex.
2.10 INPUT DATA
Take a look through the input data forms. Start by resetting the program: click on the Reset button . This returns OrcaFlex to the reset state, in which you can edit the data freely. (While a simulation is active you can only edit certain non-critical items, such as the colours used for drawing.)
Now click on the Model Browser button . This displays the data structure in tree form in the Model Browser. Select an item and double click with the mouse to bring up the data form. Many of the data items are self explanatory. For details of a data item, select the item with the mouse and press the F1 key. Alternatively use the question mark Help icon in the top right corner of the form. Have a look around all the object data forms available to get an idea of the capabilities of OrcaFlex.
End of Tutorial
We hope you have found this tutorial useful. To familiarise yourself with OrcaFlex, try building and running models of a number of different systems. The manual also includes a range of examples which expand on particular points of interest or difficulty.
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User Interface, Introduction3
USER INTERFACE
3.1 INTRODUCTION
3.1.1 Program Windows
OrcaFlex is based upon a main window that contains the Menus, a Tool Bar, a Status Bar and usually at least one 3D view. The window caption shows the program version and the file name for the current model.
Figure: The OrcaFlex main window
Within this main window, any number of child windows can be placed which may be: 3D View Windows showing 3D pictorial views of the model
Graph Windows showing results in graphical form Spreadsheet Windows showing results in numerical form Text Windows reporting status
Additional temporary windows are popped up, such as Data Forms for each object in the model (allowing data to be viewed and modified) and dialog windows (used to specify details for program actions such as loading and saving files). While one of these temporary windows is present you can only work inside that window – you must dismiss the temporary window before you can use other windows, the menus or toolbar.
The actions that you can perform at any time depend on the current Model State.
Arranging Windows
3D View, Graph, Spreadsheet and Text Windows may be tiled so that they sit side-by-side, but they must remain within the bounds of the main window. The program rearranges the windows every time a new window is created.
3.1.2 The Model
OrcaFlex works by building a mathematical computer model of your system. This model consists of a number of objects that represent the parts of the system – e.g. vessels, buoys, lines etc.
Each object has a name, which can be any length. Object names are not case-sensitive, so Riser, riser and RISER would all refer to the same object. This behaviour is the same as for Windows file names.
The model always has two standard objects:
General contains general data, such as title, units etc. Environment represents the sea, seabed, waves, current etc.
You can then use the Model Browser or the toolbar to add other objects to represent the parts of your system. There is no limit, other than the capacity of your computer, to the number of objects you can add to the model. At any time, you can save your model to a data file.
3.1.3 Model States
OrcaFlex builds and analyses a mathematical model of the system being analysed, the model being built up from a series of interconnected objects, such as Lines, Vessels and Buoys. For more details see Modelling and Analysis.