DeepCFPSO Tutorial Valid from version 4.5 2 INTRODUCTION ...................................................................................................................................................... 5 EXERCISE1 – GETTING STARTED...................................................................................................................... 7 EXERCISE2 – COUPLED ANALYSIS ................................................................................................................... 9 ENVIRONMENT ......................................................................................................................................................... 9 VESSEL ................................................................................................................................................................... 10 STRUCTURE PROPERTIES ......................................................................................................................................... 13 LINES ...................................................................................................................................................................... 14 BOUNDARY CONDITIONS......................................................................................................................................... 16 ANALYSIS ............................................................................................................................................................... 18 STATISTICAL POST-PROCESSING AND GRAPHING..................................................................................................... 20 EXERCISE3 – SIMPLIFIED MOTION VESSEL ................................................................................................ 22 VESSEL ................................................................................................................................................................... 22 SLENDER STRUCTURE ............................................................................................................................................. 22 ANALYSIS ............................................................................................................................................................... 23 STATISTICAL POST-PROCESSING AND GRAPHING..................................................................................................... 23 EXERCISE4 – SINGLE RISER ANALYSIS......................................................................................................... 26 MOTION FROM EXISTING ANALYSIS ........................................................................................................................ 26 MOTION FROM RAO-FUNCTIONS ............................................................................................................................ 26 EXERCISE5 – FATIGUE........................................................................................................................................ 28 MODELLING ............................................................................................................................................................ 28 FATIGUE ANALYSIS ................................................................................................................................................ 29 EXERCISE6 – COMBINED LOADING................................................................................................................ 31 MODELLING ............................................................................................................................................................ 31 COMBINED LOADING ANALYSIS ............................................................................................................................. 33 3 4 . All necessary input is given in the text. and to perform Exercise2/Exercise3 before Exercise4/Exercise5/Exercise6. however users that do not have the DeepC extension Coupled may perform parts of this exercise. It is based on Exercise2 or Exercise3. Exercise4 is an example of a re-analyse of one of the risers by using the vessel motion from an earlier coupled analysis. All files needed are stored in the four folders: • FPSO: Contains a complete coupled analysis example as well as an example of use of the simplified motion vessel option. Based on the FPSO coupled analysis or simplified motion example. • FPSO_Fatigue: Contains a fatigue example. The mooring lines are grouped in 4. dialog default values should be used. The intention of this exercise is to give the user an introduction to the DeepC GUI. It is based on Exercise3. This exercise requires the DeepC extension Coupled. • FPSO_Combined_loading: Contains a combined loading example including regular waves. 5 . It is however recommended to perform Exercise1 before Exercise2/Exercise3. This exercise is based on Exercise2. The water depth is 913. The FPSO is exposed to wind. In Exercise6 a combined loading analysis is performed for the risers. This exercise requires the DeepC extension Fatigue. All exercises may be done independently of each other.Introduction The system consists of the FPSO anchored to the seabed with 12 mooring lines (chain-wirechain). If nothing else is specified. You may either read in all the modelling from the js script files. current and wave loads.5m. the FPSO model is read into the application and the user examines the model. Mainly based on the FPSO coupled analysis example. Based on the FPSO simplified motion example. It is possible to partly do the modelling and partly read from files. The tutorial is separated into 6 exercises. a riser is modelled. The folder also contains the vessel geometry file T1. In Exercise2 the FPSO coupled analysis is modelled and executed. In addition.SIF. In between each mooring line group. In Exercise5 a fatigue analysis is performed for the risers. analyses based on vessel motion from RAOs are performed. • • • • • • In Exercise1. • FPSO_Single_riser: Contains an example of how to analyse a selected number of risers/mooring lines. This exercise requires the DeepC extension Code Check. or do the modelling in the DeepC GUI by following the instructions in the tutorial.FEM and the vessel characteristics file G1. Exercise3 is an example of use of the simplified motion vessel option. 6 . e. press Open. 15. Create a new workspace: File | New Workspace. Define your own display configuration and save it as MyOwn. Press the fit button and rotate. copy all files from the FPSO folder to the workspace folder you have created. 12. Choose your own workspace name and press OK. d.js: File | Read Command File … and select the file from the file list. press Save and then View to see the report in your browser. In Windows Explorer. Change the force and length unit to kipf and in respectively. Select General tab and set the background colour to your preference.Exercise1 – Getting Started 1. Hide the CLI (Command line interface): View | Tabs. press Right Mouse Button and then select Edit from the pop-up menu. Start the DeepC application and ensure at least the Riser or Coupled feature option is selected in the select features dialog. Inspect some of the items in the folders and sub-folders by using RMB | Edit. Press OK. 5. b. Turn on Show Tracbal and Show Rotation Centre c. otherwise read the file Read_Simplified_motion. Open the vessel dialog: RMB | Vessel Data | Vessel Data … on the vessel Vessels/FPSO and browse through some of the tabs. Save a report to document the model: File | Save report … Select HTML as Report type. Open the on-line user documentation: Help | Help Topics … and inspect the manuals and JScript commands. i. Inspect the contents of the folders: Analysis Environment Structure Structure Properties Vessels 9. 11. 10. 14. 7. 4. If you have the DeepC extension Coupled (for doing coupled analysis) read in the js script file Read_FPSO. 7 .js. Switch to the Settings tab and select different display configurations e. Open the input units dialog: Edit | Rules | Units. Open the view options dialog: View | Options … a. Save and close the workspace: File | Close Workspace. 2. 8. zoom and pan the model. 6. 13. 3. Bring up the vessel dialog again and watch the effect of changing the input units. 8 . 0001m. Create a direction DirCurr: RMB | New Direction … on folder Environment/Directions.02. Then create the directions DirWave=180deg and DirWind=121deg. 4. Create a NPD wind spectrum NPD1: RMB | Wind Spectrum | New NPD … on folder Environment/Air and select the NPD wind spectrum tab. and set the Force unit to kN.Exercise2 – Coupled Analysis This exercise requires the DeepC extension Coupled.5 Seabed normal (dummy value) Vector3d(0. Create a seabed property floor: RMB | New Seabed property … on folder Environment/Soil. Create a Jonswap 3 parameter wave spectrum Wave_spec: RMB | Wave Spectrum | New Jonswap 3 Parameter … on folder Environment/Water. 9 .025m Wind profile exponent 0.125 Average wind velocity 41. Specify the angle as 211deg and press Apply.1) Seabed property floor Press OK. Press OK. 1. Create a wind profile windProf1: RMB | New Exponential Wind Profile … on folder Environment/Air. Start the DeepC application and ensure the Coupled feature option is selected in the select features dialog. 3.19m Peak period 14s Press Apply | Cancel. copy all files from the FPSO folder to the workspace folder you have created. Select the Soil tab and specify the following values Seabed Z (mudline) -913. 8. Peakedness 2. In Windows Explorer. Specify tolerant modelling: Edit | Rules | Tolerances. 10. 6. Specify reference height. toggle on the Use tolerant modelling check box and specify the Point Tolerance to 0.13m/s Press Apply | Cancel. Press Apply | Cancel. Choose your own workspace name. 9. wind profile exponent and wind velocity according to the table Reference height 0. 2. Create a location and name it Hurricane_location: RMB | New Location … on folder Environment. Specify peakedness wave height and period.0. Normal stiffness 25 KPa Longitudinal stiffness 0 Transversal stiffness 0 Longitudinal friction coefficient 0 Transverse friction coefficient 0 Press Apply | Cancel. Specify surface friction coefficient as 0. Create a new workspace: File | New Workspace. 7. Toggle on the Set Database Units check box. Environment 5.5 Significant wave height 12. Specify stiffness and friction coefficients. For the Hurricane_location create an irregular time condition Hurricane_condition: RMB | New Irregular Time Condition … on the location Environment/Hurricane_location. Specify wind data Direction DirWind Wind profile windProf1 Wind spectrum NPD1 Random seed wind 1 b. Select the Current tab and toggle on the Include current check box. Specify current data Direction DirCurr Current profile CurProf1 Press Apply | Cancel. If you did not complete the Environment session. Specify the profile.2s Low frequency time step (dummy value) 0. e. Select the Wind Sea tab and toggle on the Include Wind Sea check box. Duration 10800s Time step 0.11. which always will be equal a power of 2 time steps. Specify wind sea data Direction DirWave Wave spectrum Wave_spec Random seed wave 1 Do not specify any wave spreading. Z Direction Velocity 0 0 1.293m/s -261.82m 0 0.5s The actual duration field in the dialog shows the actual duration of the pre generated time series. Specify duration and time step. Open the new workspace dialog: File | New Workspace b.09144m/s -913. c.5m 0 0.g. ws_FPSO from the Location field to the Workspace name field 10 . 13. Create a current profile CurProf1: RMB | New Current Profile … on folder Environment/Water. Save the workspace Vessel 14. Cut/paste the workspace name. Select the Air tab and toggle on the Include wind check box. 12. a.09144m/s Press Apply | Cancel. you may prepare for this session by doing the following: a. SIF: RMB | Read Vessel Data … on vessel Vessels/FPSO. all your earlier modelling will now be lost.js and Environment.5m Select the points in the browser and observe the points being highlighted in the 3D window. e. 15. name the two points origo and turret: RMB | New Guide Points … on folder Utilities/Guiding Geometry/Points. Do not change the data base unit.45m 0 -16. origo 000 turret 61. (Note that since we do not change the workspace name.) d. Open the file Read_FPSO. You may consider making a backup of your js file from the environment session. 16. Press OK. Create a vessel FPSO: RMB | New Vessel … on folder Vessels. Select Line dependent coupled motion and specify position and orientation Vessel initial position 000 Vessel orientation about local X axis 0 Vessel orientation about local Y axis 0 Vessel orientation about local Z axis 0 Press OK 17.js files into the CLI window. Create guiding points for the origin and turret position. 11 . Answer No to the questions about re-generating the database and saving workspace database file.c. or creating a workspace with a new name. Read vessel data from file G1.js in an editor and copy/paste the commands reading the Initiate. Create 5 vessel fairleads: RMB | Vessel Data | Fairleads … on vessel Vessels/FPSO Hint: By selecting points in the 3D graphical window the coordinates in the currently active row in the grid will be filled out. 20. Press OK d. Specify Single(XZ) Symmetry.e. Press Apply and inspect the fairlead symbols appearing in the 3D window. Press OK. Select tab Linear Damping and specify linear roll damping C44=1520000 kNsm. To compensate for the pretension from the riser and mooring lines. The vessel data specification must be modified. Specify wind force coefficients by reading in the js file Wind_coefficients. e. Specify quadratic current coefficients by reading in the js file Current_coefficients. Open the FPSO Support Vessel dialog and select tab Wind Force. to Vessel. Vessel Mass. The FPSO is turret moored. The next step is to model the fairlead position. We will therefore create 4 fairleads close to the turret and one fairlead at the turret. change the display configuration . however only one line can be connected to each ball joint. a rotation free boundary condition may be modelled by using a ball joint in the connection between a line and the fairlead. Hydrostatic Restoring and Vessel RAO.js. Again. a. i.js.18. RMB | Vessel Data | Specified Force on vessel Vessels/FPSO 12 . 22. and select the tabs Vessel Data. Read vessel geometry from file T1. and press the fit button . Open the FPSO Support Vessel dialog and select tab Quadratic Current. 19.FEM: RMB | Read Vessel Geometry … on vessel Vessels/FPSO. specify a vertical force of magnitude 19367kN pointing upwards. Inspect the coefficients and specify additional data Symmetry Single(XZ) Wind force area 2000m^2 Reference height 10m Press OK 21. Select tab Vessel Data and specify Single(XZ) Symmetry. Inspect vessel characteristics read from the SIF file: Open the support vessel dialog by doing RMB | Vessel Data | Vessel Data …. and both the 12 anchoring lines and the 4 risers are connected to the vessel at the turret. open the FPSO Support Vessel dialog. Select tab Artificial Stiffness and specify stiffness coefficients Surge 1000 kN/m Sway 1000 kN/m Heave 1000 kN/m Roll 1000000 kNm Pitch 1000000 kNm Yaw 1000000000 kNm Press Apply c. In a coupled analysis. On the view manipulations toolbar. Thus each of the four risers (which have bending stiffness) must have its own fairlead. Press Apply b. 23. 26.3m Inner diameter 0.2s as time step and press Calculate. Calculate retardation functions: RMB | Vessel Data | Calculate Retardation Function on vessel Vessel/FPSO. 24. Use 75m as element length. Structure properties 25.28m Radius of gyration 0. Use 0. you may prepare for the present session using the same procedure as described in the beginning of the Vessel session. Buoy part Bare part Property name riser_buoy riser_bare Mass pr length 0.2 1. Create the riser axi-symmetric properties riser_buoy and riser_bare: RMB | New Section Axi-Symmetric … on folder Structure Properties/Sections.2 Longitudinal added mass 0 0 Transverse added mass 1. Create the property for the internal fluid in the riser InternalFluid1: RMB | New Internal Fluid… on folder Structure Properties/Slender Components The parameters for pressure and surface elevation is not used and thus disabled in the dialog.65m 0. RMB | New Mesh Density on Segment on folder Structure Properties/Mesh Densities. Create the mesh density property for the buoy part of the riser mdens _riser_buoy. a. Then create the mesh density for the upper and lower part mdens_riser_up and mdens _riser_low.228tonne/m 0.28m 0.3m b. Buoy part Bare part Property name hydro_riser_buoy hydro_riser_bare Longitudinal quadratic drag 0 0 Transverse quadratic drag 1. Use 50m as element length for both properties.0 Hydrodynamic diameter 0.181tonne/m Axial stiffness 50000000kN 50000000kN Bending stiffness 21500kNm^2 21500kNm^2 Torsional stiffness 16500kN*m^2/rad 16500kN*m^2/rad Outer diameter 0. Inspect some of the calculated functions.15m 0. Save the workspace.65m 0. If you did not complete the previous session.15m c. The risers consists of a buoyancy middle segment and an upper and lower bare segment.0 1. d. Create the riser hydrodynamic properties hydro_riser_buoy and hydro_riser_bare: RMB | New CD Segment … on folder Structure Properties/Load Interfaces. 13 .Use a large value as the end time. The riser has its End1 at the fairlead and End2 at the seabed. Place the cursor in the End 1 field in the line dialog window and select the fairlead position from the 3D window . 31. Save the workspace. and then the remaining three risers are created by using the first riser as a template. i. h. click on it. Create the properties for the mooring lines by reading in the js file Mooring_line_properties. Define the 3 riser segments: Type in the segment name and segment length. Set Rotation X. Set the display configuration to Structure Concepts. Hint: You may copy/paste rows in the table.js. i.fairlead(“riser1_conn ect”) in the browser. Create a component buoy property Component1: RMB | New Component Buoy … on folder Structure Properties/Slender Components. 32. and create guiding points for the riser connection to the seabed by reading in the js file Riser_anchor_positions. 29. Toggle on the Compute kinematics check box and specify computation at every 1 node. Create a rotation hinge property RotationHinge1: RMB | New Rotation Hinge … on folder Structure Properties/Slender Components. d. Since the ball joint here only represents the boundary condition. Highlight the riser1 fairlead position by selecting the fairlead Vessels/FPSO/FPSO_Fairleads/FPSO. you may prepare for the present session using the same procedure as described in the beginning of the Vessel session. e. Inspect the new properties. c.js. If you did not complete the previous session. To model the rotational free boundary condition between the riser and vessel fairlead. 14 .Y and Z as free. Create riser riser1: a. physical extension and hydrodynamic property. Lines 30. Specify all values as zero. Create a CD buoy property HydrodynamicLoad1: RMB | New CD Buoy … on folder Structure Properties/Load Interfaces. A ball joint must however consist of a component buoy and a CD buoy property as well as a rotation hinge property. f. 28. c. RMB | New Line … on folder Structure b. Toggle on the Internal fluid check box and select InternalFluid1. We start by creating one riser from scratch.27. CD segment and mesh density. a. we are in the present example using a ball joint. Rotate (RMB) the model to a proper orientation. Place the cursor in the End 2 field and select the anchor position from the 3D window g.e. and select the correct properties for section. Use rubber band (shift+CTRL+RMB) to zoom in the highlighted fairlead. Press the fit button and highlight the guiding point apr1. The four risers are equal except for the fairlead and seabed coordinates. We will now pick the end points from the 3D window. Specify zero value for the mass and volume. b. it will have zero values specified for the mass. Create riser3 and riser4. 35. End 1 is at the fairlead. 34. c. and name the riser riser2. Press Calculate and observe that the distance between the endpoints becomes equal to the length of the lines. 33. b. b. Toggle on the View stress free configuration check box. Calculate the stress free coordinates for the risers and mooring lines: a. d. RMB | Edit Line … on line Structure/riser1. End1 and Calc. End2 for all the lines.j. Press OK and observe the line appearing in the 3D window. Select the End 1 and End 2 positions in the same manner as for riser1. Select all the lines in the browser by using LMB (Left mouse button) while you are holding the SHIFT keyboard button down. Then hide the stress free configuration: RMB | Hide Stress Free Configuration on folder Structure. Select New. RMB | Stress Free Coordinates … on folder Structure.js. Hint: Select all lines by clicking in the column header. RMB | Compute Line Shape and press OK. b. c. Select Calc. The second riser is created by using riser1 as a template: a. Use the built in cable solver to calculate the line shape for all the lines: a. Press OK and observe the stress free configuration appearing in the 3D window. 36. Create the 12 mooring lines by reading in the js file Mooring_lines. 37. 15 . Observe the computed shape in the 3D window 38. you may prepare for the present session using the same procedure as described in the beginning of the Vessel session. 16 . Save the workspace. Highlight the guiding point apr1. 40. Boundary conditions 39. If you did not complete the previous session. Specify zero as the angle with global XY-plane.c. Create the boundary condition for the first riser and name it Sup_r1: RMB | New Support … on folder Structure. The stress free to static rotation should be Calculated from angle with global XY-plane. Click in the Point field in the Support Point dialog and select the anchor position from the 3D window. Specify the boundary condition as fixed in all modes. Name the ball joint BallJoint1 d. 17 . Press the First End radio button. 41. This is why we have to use the ball joint): a. c. Cd buoy and Rotation hinge.Then create the boundary conditions for the remaining three risers in a similar way. Open the ball joint dialog: RMB | New Ball Joint … on folder Structure/Ball Joints. We will now create the ball joint used as a rotation free connection between the riser and the vessel fairlead. e. (In a coupled analysis. Zoom in the fairleads in the 3D window. Select riser1 and riser_up in the Line and Segment combo box. Select properties for the Component buoy. the fairlead boundary condition must be fixed in all modes. b. 42. and select Coupled as Motion Type. Select Hurricane_condition in the Irregular time condition combo box. Open the response storage dialog: RMB | Response Storage on the analysis object Analysis/Ana100Y. Create the remaining three ball joints BallJoint2.5 0.5 0.5 18 . Select the Force Response tab and specify storage according to the table Line name Segment name From position To position Line1 FairleadChain 0 0 Line12 FairleadChain 0 0 riser1 riser_up 0 1 riser1 riser_buoy 0.f. Select the Nodal Response tab and specify storage according to the table Line name Segment name From position To position Line1 FairleadChain 0 0 Line12 FairleadChain 0 0 riser1 riser_up 0 0 riser1 riser_buoy 0 0 riser2 riser_up 0 0 riser2 riser_buoy 0 0 c. Create a coupled analysis Ana100Y: RMB | New Analysis … on folder Analysis.BallJoint3 and BallJoint4.5 riser2 riser_low 0.5 0. 47.5 riser2 riser_up 0 1 riser2 riser_buoy 0. 44. b. You may adjust the symbol size from the view options dialog: View | Options. Save the workspace. 43.5 0. Press Apply and observe the ball joint symbol appearing in the 3D window. 46. Analysis 45. select Settings tab and open folder Structure/Ball Joint. Press OK. you may prepare for the present session using the same procedure as described in the beginning of the Vessel session. If you did not complete the previous session.js. Create the boundary conditions for the mooring lines by reading in the js file Support_mooring_lines. Specification of response storage: a.5 riser1 riser_low 0. 53. When the static analysis has finished. Open the static analysis options dialog: RMB | Static analysis Options … on the analysis object Analysis/Ana100Y. View the result files by pressing the result file buttons. 54. Step through the static load sequence and watch the results in the 3D window. To reduce the CPU time needed in this exercise. Press Run Analysis to execute the static analysis. check for possible errors in the analysis control dialog. 52. Select the Irregular Response Analysis tab. Select Input Module and Static. a. Set the display configuration to Static Result and view the static configuration: RMB | View Static Configurations … on analysis object Analysis/Ana100Y.48. Inspect the static line and vessel results in the Results/Static Results folder. Read static results: RMB | Read Static Results on the analysis object Analysis/Ana100Y. Toggle on the Automatic regenerate input files check box and toggle off the Run in background check box. you may consider specifying a small value as the Simulation length 19 . 50. as one can only run different parent analyses in parallel. Open the analysis control dialog: RMB | Execute Analysis … on the analysis object Analysis/Ana100Y. Open the dynamic analysis option dialog: RMB | Dynamic analysis Options … on analysis object Analysis/Ana100Y. Select the Load Sequence tab and specify values according to the table 49. The number of parallel analyses doesn’t matter. 51. Place the marker in the graph window and RMB | Zoom All to fit the graph in the window again.1s and keep the remaining default settings. Compute the probability distribution for riser1 at the fairlead: RMB | Compute Probability Distribution. Change the spectral smoothing parameter: Edit | Rules | Response Post Processing. Select the Animation setup tab. 66. View the motion path. Save and close the workspace. Inspect the vessel time series results in folder Results/Dynamic Results/Vessel Time Series. 56. 65. Compute the spectrum for the riser1 tension at the fairlead: RMB | Compute Spectrum.js. b. Read dynamic results: RMB | Read Dynamic Results on analysis object Analysis/Ana100Y. Zoom in on the graph using shift + RMB in the graph window. 64. Read the file Read_FPSO. Keep the remaining default settings.g. Read in the dynamic line and vessel results. Select Dynamic and press Run Analysis to execute the dynamic analysis. The computed spectra are stored in folder Results/Dynamic Results/Spectra. The file may be read into Xtract for animation of the vessel and line motion. For the analysis object Analysis/Ana100Y specify 3600s as the simulation length and execute the static and dynamic analysis. e. i. Toggle on the Produce animation check box and specify Ana100Y as the Animation file name. Make a graph of the FPSO motion path in the XY plane: In folder Results/Dynamic Results/Vessel Time Series select both FPSO_GlobalPostition_X and FPSO_GlobalPosition_Y using ctrl+LMB and then do RMB | Parametric Graph. or if you want to increase the length of your time series results before post-processing. Do not close the graph window. Open the analysis control dialog. The computed distributions are stored in folder 20 . Press Apply. 61.e. c. Select the Non-linear iteration Procedure tab and specify Step Subdivisions as 16. 100s. 57. The filtered time series are stored in folder Results/Dynamic Results/Filtered Time Series. 60. Set the Time step to 0. File | New Workspace and keep your old workspace name. Inspect the range results in folder Results/Dynamic Results/Range Curves. c. Statistical post-processing and graphing 59. d. View the computed spectra. b. Plot the Max/Min effective tension range for riser1: RMB | Range Max/Min. Restart the workspace as new.vtf will then be created. do the following: a. Keep the remaining default settings. 63. Press Apply. 55. Change the Spectral Smoothing Coefficient from 7 to 15 and press OK. 62. Read vessel results: RMB | Read Vessel Results on analysis object Analysis/Ana100Y. Graph the line tension at the fairlead of riser1: RMB | Display Graph on item Results/Dynamic Results/Line Time Series/ riser1_riser_up_Element_1_Te. Inspect the line time series results in folder Results/Dynamic Results/Line Time Series. Low pass filter the FPSO X and Y motion time series: RMB | Low Pass Filter. Press OK. 58. A file Ana100Y.instead of a more realistic value. Re-compute the spectrum for the riser1 tension at the fairlead and compare the graph with the earlier computed spectrum. If you did not complete the previous session. 67. 21 . Save and close the workspace.Results/Dynamic Results/Distributions. Then plot the Weibull distribution: RMB | Display Probability Distribution. Plot the Weibull distribution on Weibull paper: RMB | Weibull Graph. name the fairlead turret and press Apply.45. Select Vessel Data tab and specify Single(XZ) symmetry.e.js in an editor. Press OK. Select Fairleads tab and define a vessel fairlead in the turret position (61. 8. For the turret fairlead press Set Boundary Conditions and change the X. 6. is identical to the environment session in the Coupled Analysis exercise.0 and turret=61. Lines and Boundary Conditions. Create a new workspace: File | New Workspace. d. Start the DeepC application and ensure the Riser feature option is selected in the select features dialog. You may either do the environment modelling by following the instructions in Exercise2. (do not close the fairleads dialog).FEM: RMB | Read Vessel Geometry … on vessel Vessels/FPSO. Press Apply.0.e. From the Coupled Analysis exercise. The first part of this exercise. 3.-16. Close the support vessel dialog.Z rotation degree of freedom to Free. Copy all files from the FPSO folder to the workspace folder you have created. 9.js file into the CLI window: 22 . 5. the environment modelling.Exercise3 – Simplified Motion Vessel 1. Open the support vessel dialog: RMB | Vessel Data on the vessel object. c. or you may skip it by doing the following: a. i. Choose your own workspace name and press OK. and paste the following read file commands into the CLI window: Vessel 2. Select Simplified motion and specify the vessel initial position to be at origin and the vessel orientation as zero. Create guiding points origo=0. 7. Exercise2.Y.45m.-16. 4. i. Alternatively you may paste the following read file commands from the Read_Simplified_motion. Read vessel data from file G1. b.0.0.5m: RMB | New Guide Points … on folder Utilities/Guiding Geometry/Points. Create a new vessel FPSO: RMB | New Vessel … on folder Vessels.SIF: RMB | Read Vessel Data … on vessel Vessels/FPSO. perform the three sessions: Structure Properties. Slender structure 10.5). Open the file Read_Simplified_motion. Read vessel geometry from file T1. Note: We are now performing a simplified motion analysis (uncoupled) where the risers and mooring lines do not have any impact on the vessel motion or the response of the other lines. Select Time series on file as Motion Type. File | New Workspace and keep your old workspace name. d. Read in the dynamic line results. Columns=1. For the second load group replace the number of steps. 23 . Read the file Read_Simplified_motion.3. 14.7 13. Open the edit dialog for riser1-riser4 and move the End1 position to the turret fairlead. a. Graph the line tension at the fairlead of riser1: RMB | Display Graph on item Results/Dynamic Results/Line Time Series/ riser1_riser_up_Element_1_Te.js. Select Hurricane_condition in the Irregular time condition combo box b. Compute the spectrum for the riser1 tension at the fairlead: RMB | Compute Spectrum.txt. i. a. View the computed spectra. Angle Unit=Degrees g. 16. Specify a small value as Simulation length. Analysis 12. Place the marker in the graph window and RMB | Zoom All to fit the graph in the window again. Create a new analysis Ana100Y: RMB | New Analysis … on folder Analysis. c. Statistical post-processing and graphing 19. If you did not complete the previous session. Hint: For a more detailed explanation of this and the remaining steps in this section. Read in and view the results. see similar steps in the Analysis section in Exercise2. do the following: a. Open the static analysis options dialog and select the Load Sequence tab. Open the response storage dialog. Do not close the graph window. c. Zoom in on the graph using shift + RMB in the graph window. Save and close the workspace.4. Restart the workspace as new. Press OK.e. 18. 21. 11. by 200. b. 20. File Type=ASCII e. and specify storage of force and nodal response. Open the dynamic analysis options dialog and Irregular Response Analysis tab. Reference System=Dynamic Displacement f. Recalculate the stress free coordinates for the risers.e. e. 100s and set the Time step to 0.2. d. File Name=Motion_FPSO. i. c.g. Open the analysis control dialog and execute the static and dynamic analysis.5. b. 15. The computed spectra are stored in folder Results/Dynamic Results/Spectra. In an uncoupled analysis we do not need to use ball joints when modelling fairlead boundary conditions as free in the rotational modes. Delete the four ball joints BallJoint1-BallJoint4. Keep the remaining default settings. The user may therefore delete lines for which results are not wanted. 17.05s. or if you want to increase the length of your time series results before post-processing.6. For the analysis object Analysis/Ana100Y specify 3600s as the simulation length and execute the static and dynamic analysis. 20. 24 . 24. 25. Change the Spectral Smoothing Coefficient from 7 to 15 and press OK. Inspect the range results in folder Results/Dynamic Results/Range Curves. Compute the probability distribution for riser1 at the fairlead: RMB | Compute Probability Distribution. The computed distributions are stored in folder Results/Dynamic Results/Distributions.22. Save and close the workspace. Re-compute the spectrum for the riser1 tension at the fairlead and compare the graph with the earlier computed spectrum. Then plot the probability distribution: RMB | Display Probability Distribution. 23. Plot the Max/Min effective tension range for riser1: RMB | Range Max/Min. Plot the probability distribution on Weibull paper: RMB | Weibull Graph. Change the spectral smoothing parameter: Edit | Rules | Response Post Processing. 25 . Create a new analysis by copying Ana100Y. 8.) 9. (To rename an analysis. For the coupled analysis Ana100Y. Motion from RAO-functions 11.js in an editor and paste the following commands into the CLI window.js by Read_Simplified_motion.Exercise4 – Single Riser Analysis 1. Choose your own workspace name and press OK.g. 100s. 26 . 10. Start the DeepC application and ensure the Coupled and/or Riser feature option is selected in the select features dialog 2.) Motion from existing analysis 5. Specify the Motion Type to “Time series from existing analysis” and select Ana100Y as the Analysis. you have to skip step 14b. Create a new workspace: File | New Workspace. e.g. Run the coupled analysis Ana100Y and read static results and the dynamic line results. (The first part of this exercise. e. If you do not have this license option you may still do parts of the exercise. press Open. If you did not complete the previous session. 4. do the following: Restart your workspace as new. 3. and name the new analysis Motion_Ana100Y. the Motion from existing analysis session requires the DeepC extension Coupled. Replace the file Read_FPSO. Read in the js script file Read_FPSO. do RMB | Rename on the analysis object. toggle on No Storage for the respective lines and press Apply. In Windows Explorer copy all files from the FPSO and FPSO_Single_riser folders to the workspace folder you have created. 6.js and perform step 6. Delete all risers and mooring lines.Line12 and riser2: RMB | Response Storage … on object Ana100Y. Edit the analysis Motion_Ana100Y: RMB | Edit.js: File | Read Command File … and select the file from the file list. specify a short time as simulation length. remove response storage for Line1. Some adjustments may be necessary. 7. except riser1. Select the Nodal Response and Force Response tab. Then jump to the Motion from RAO-functions session. read in the results and compare with results from Ana100Y. i. Then open the file Read_Single_riser.e. To reduce the CPU time needed in this exercise. Execute the analysis Motion_Ana100Y. which is an approximation of the result from the coupled analysis. 14.12. Remove all FPSO fairleads except riser1_connect: RMB | Vessel Data | Fairleads … on vessel Vessels/FPSO. 18. so to include a static rotation about the vertical axis we have to change the initial vessel position and orientation. Create a new analysis by copying Ana100Y. Open the vessel data dialog: RMB | Vessel Data | Vessel Data on the vessel object. Select the fairleads to be removed and press the Delete keyboard button.e. Specify the Motion Type to RAO-functions. The static displacement of the vessel due to wind. read in the results and compare with Ana100Y. do a re-modelling: a. Open the edit dialog for riser1 and move the End1 position to the fairlead position. b. read in the results and compare with RAO_offset. and name the analysis RAO_remod. 27 . Recalculate the stress free coordinates for riser1. Execute the analysis RAO_offset. 17. and modify the values for position and orientation to b. current and mean wave forces may be included by using the X/Y-offset option. and name the analysis RAO_offset. 15. The static vessel position from the coupled analysis Ana100Y was found to be It is not possible to include a yaw motion as a static offset in the analysis. Execute the analysis RAO_remod. c. Press OK. Create a new analysis by copying Ana100Y. Specify the Motion Type to RAO-functions. Edit the analysis RAO_offset: a. 13. Specify the offset in x-direction to 30m. Save and close the workspace. i. d. 16. do not specify any offset. Hint: Set B8_16 as active. Copy all files from the FPSO and FPSO_Fatigue folders to the workspace folder you have created. The scatter diagram may alternatively be read form file Scatter. Create an irregular scatter diagram and name it Scatter1: RMB | New Scatter Diagram … on location Environment/Hurricane_location. Then include the cell for Hs=6m. profile=windProf1. Start the DeepC application and ensure the Fatigue feature option is selected in the select features dialog. 8. Define multiple wave spectra: RMB | Multiple wave spectrums… on the scatter discretization object. Specify 28 . Read in the js script file Read_FPSO. then read in the file Read_Simplified_motion.Exercise5 – Fatigue This exercise requires the DeepC extension Fatigue. press Open. 3. c. Use four blocks and one bin for each block. press All Jonswap. Start by specifying Delta Hs=5m and Delta Tp=5s and use the Auto fill all button. Do not reuse any of the wave spectra. Specify all spectra as Jonswap 3 parameter. and use the default values for the parameter Gamma. 10. a. Create a new workspace: File | New Workspace. Hint: For a faster modelling. 2.e. 7. 4. or do not want to base your fatigue analysis on a coupled motion analysis. spectrum=NPD1. Create the riser stress concentration factor and name it Scf1: RMB | New Stress Concentration Factor … on folder Structure Properties/Fatigue. 9. Modelling 5. d. Choose your own workspace name and press OK. Include wind: direction=DirWind.js. Inspect the Environment/Water folder and click on the scatter discretization object to see the new spectra and irregular time conditions that has been created. Include current: direction=DirCurr and profile=CurProf1. copy and paste the name of the directions etc. Create the scatter discretization and name it ScatterDiscretization1: RMB | New Scatter Discretization … on scatter diagram Environment/Hurricane_location/Scatter1. Tp=14m in the block B8_16. (This requires the DeepC extension Coupled.js): File | Read Command File … and select the file from the file list. 2m 4m 6m 8m 10m 2s 4s 6s 8s 10s 12s 14s 16s 1 2 4 5 7 4 4 5 2 3 5 6 3 3 2 2 4 4 2 2 1 3 3 2 1 1 1 18s 12m 6. double click the cell and remove B10_15. Define multiple irregular time conditions: RMB | Multiple irregular time conditions… on the scatter discretization object. b. Use wave direction DirWave for all blocks. i. Auto fill names by clicking the Name column header. into the cells in the table. 1.js. If you do not have this license option. 16. Select DnV-B1_Seawater-cathodic from the Predefined curves combo box and press Fill with predefined. Since you are performing fatigue analysis on the risers only.00020435m^4 Crossectional area 0.g.js in an editor and paste the following commands into the CLI window (If you base your fatigue analysis on a simplified motion vessel. Press OK. 14. 12. Repeat the last two steps for riser2. e. 100s in the analysis template Ana100Y. (If you base your fatigue analysis on a simplified motion vessel. Assign the properties to all segments of the riser. Assign the structural fatigue properties to riser1. Create an irregular fatigue analysis and name it Fatigue1: RMB | New Fatigue Analysis … on folder Capacity/Fatigue Analysis. if you do not have the DeepC extension Coupled.js should be used.the factor as a constant value of 1. riser3 and riser4. Execute the analyses: RMB | Execute Multiple Analysis … on folder Analysis. To reduce the CPU time needed in this exercise. Hint: Press the column header to select all analyses. you may also remove the mooring lines which will not have any impact on the vessel motion and hence the riser response. specify a short time as simulation length. Define force storage for all elements of riser1 15. e. 29 . which will be the basis for the fatigue analysis later on: RMB | Multiple Analysis … on folder Analysis. The Ana100Y analysis will be used as an analysis template when creating the analyses for the fatigue calculation.02m 13.0094m^2 Diameter 0. then you may specify the Motion Type to RAO-functions and specify the offset in x direction to 30m. 17.) 18.) 20.3m Thickness 0. Set the Motion Type to Coupled. open the file Read_Fatigue. Select scatter discretization and analysis template. Create the multiple analyses. 11. Select outer wall as the radial position for calculation of bending stress. RMB | Edit Fatigue Properties on line Structure/riser1. Specify values according to the table. Create the SN-curve and name it SNCurve1: RMB | New SN Curve … on folder Structure Properties/Fatigue. Create the stress crossectional parameters StressProperties1: RMB | New Section Stress Parameters … on folder Structure Properties/Fatigue. Auto-fill names by clicking the Name column header. the file Read_Fatigue_Simplified_motion.g. Moment of inertia 0. If you did not completed the Modelling session then restart your workspace as new. Fatigue Analysis 19. Use rubber band or click the segments directly. Go to the folder Results/Fatigue Results/Fatigue Life and plot the fatigue life for riser1 along the line. View the fatigue listing file: RMB | Show Fatigue Listing File … on item Capacity/Fatigue Analysis /Fatigue1. 25. 29. Try the values 10000. Save and close the workspace. Create a new fatigue analysis with 4 hotspots. The reason for computing the line shape is to have a more realistic view of the risers when inspecting the fatigue contour plot later on. Set the radio button to irregular and select the scatter dizcretisation ScatterDiscretization1. Select Fatigue1 and run the fatigue analysis by pressing the Start button. plot the fatigue life in the same figure. 27. 30 .a. b. Open the fatigue Activity Monitor dialog: RMB | Run Fatigue Analysis… on item Capacity/Fatigue Analysis /Fatigue1. 23. 24. Hint: Copy/paste your first fatigue analysis Fatigue1 and edit the number of hotspots. 22.e. 1000 and 100. Set the display configuration to Fatigue Result and view the fatigue contour plot in the 3D window.) Press Add Select button to fill the table with selected segments. 26. and compare the fatigue life with results from Fatigue1. i. Compute the line shape for the risers. The probability is one when you have only one discretization. Select all the segments for the risers from the 3D window. Specify number of hotspots to 16. 21. Lower the max value to get a better understanding of the fatigue life along the risers. Run the newly created fatigue analysis. Open the fatigue color palette dialog: RMB | Edit Contour Color Palette … on item Capacity/Fatigue Analysis/Fatigue1. (Remember to press the segment selection button and use LMB to select. The shape of a line needs to be calculated before the fatigue analysis is performed. 28. i. with wave directions 45 and 90 degrees respectively. Start the DeepC application and ensure the Code Check feature option is selected in the select features dialog. 7. 9. Read in the js script file Read_Simplified_motion. Specify the angles as 0. so start by deleting all mooring lines Line1Line12 and riser2 and riser4. 1.js.e. and specify wave data Direction Direction0 Component RegularWave14x10 Wave model Airy b.3 Yield 480000 KPa Strength ration 1. 6.2 Fabrication strength reduction factor 1 11. 31 . uncoupled analyses. and ensure that the Include current check box is toggled off. Young 205000000 KPa Poisson 0. Select the Wave tab. Direction45 and Direction90: RMB | New Direction … on folder Environment/Directions. Create the combined loading pipe section property PipeCombinedLoading1: RMB | New Pipe Combined Loading … on folder Structure Properties/Combined Loading. Modelling 5. For the wave periods analysed. Copy files from the FPSO and FPSO_Combined_loadinge folders to the workspace folder you have created. vessel responses are obtained from the value of the motion transfer function at the particular wave period. Press Apply | Cancel.Exercise6 – Combined Loading This exercise requires the DeepC extension Code Check. 4. Specify period and height according to the table Period 14s Height 10m Press Apply | Cancel. Specify values according to the table. 10. Specify values according to the table. a. Create 3 directions Direction0. Select the Current tab. Create a regular wave RegularWave_14x10: RMB | New Regular Wave … on folder Environment/Water.: File | Read Command File … and select the file from the file list. press Open.45 and 90 degrees respectively. Create a new workspace: File | New Workspace. Create the combined loading material property MatierialCombinedLoading1: RMB | New Material Combined Loading … on folder Structure Properties/Combined Loading. 3. Choose your own workspace name and press OK. You may need to resize the dialog window to be able to type in the whole condition name. 2. We will only analyse riser1 and riser3. For the Hurricane_location create a regular time conditions RegCond_14x10_D0: RMB | New Regular Time Condition … on the location Environment/Hurricane_location. 8. The combined loading analyses which will be performed in this exercise are based on riser force values calculated by regular wave time domain analyses. Create two additional regular time conditions RegCond_14x10_D45 and RegCond_14x10_D90. Specify the Motion Type to RAO-functions.Nominal Diameter 0. 32 . Create the combined loading fluid property FluidCombinedLoading1: RMB | New Fluid Combined Loading … on folder Structure Properties/Combined Loading. Do Copy/Paste of Ana_template. The parts of the risers to be included in the combined loading analysis need to have storage of force response specified. Create the analysis AnaReg_14x10_D0. Create analysis template Ana_template: RMB | New Analysis … on folder Analysis. 19.002 m 12. 14. Specify values according to the table.8 tonne/m^3 Internal Pressure 34500 Kpa Internal Z-ref 50 m 13. a. Execute the analyses: RMB | Execute Multiple Analysis … on folder Analysis. Select the Force Response tab and specify storage according to the table Line name Segment name From position To position riser1 riser_up 0 1 riser1 riser_buoy 0 1 riser1 riser_low 0 1 riser3 riser_up 0 1 riser3 riser_buoy 0 1 riser3 riser_low 0 1 18.2445 m Nominal Thickness 0. Hint: Press the column/row header to select/deselect all analyses.0172 Ovality 0. Specify the value for Steps per periods to 50. Open the static analysis options dialog: RMB | Static analysis Options … on the analysis object Analysis/Ana_template.001 m Internal corrosion/wear 0. modify the names and refer to the relevant regular time condition. 15. AnaReg_14x10_D40 and AnaReg_14x10_D90. Select the Regular Response Analysis tab. Do not specify any offset. Select Regular time condition and the condition RegCond_14x10_D0 from the combobox. Open the dynamic analysis options dialog: RMB | Dynamic analysis Options … on analysis object Analysis/Ana_template. Open the response storage dialog: RMB | Response Storage on the analysis object Analysis/Ana_template. Keep also the default settings for the other parameters. Select the Load Sequence tab and specify values according to the table Steps Iteration Tolerance Type1 Type2 200 200 1e-006 VOLU SFOR 200 200 1e-006 DISP 20 200 1e-006 FRIC 16.01 External corrosion 0. and keep the default value 10 for the Number of periods. RMB | Edit Combined Loading Properties on line Structure/riser1. Assign the combined loading properties to riser1 and riser3. 17. Assign the fluid properties to the lines and the material and pipe property to all the segments. External Density Reuse External Pressure Reuse External Z-ref Reuse Internal Density 0. c.Combined Loading Analysis 20.js in an editor and paste the following commands into the CLI window 21. d. If you did not completed the Modelling session then restart your workspace as new. We are now going to create a number of combined loading analyses based on the template. 33 . Specify the value to 3. Use rubber band or click the segments directly.) Press Add Select button to fill the table with selected segments. a. AnaReg_14x10_D45 and AnaReg_14x10_D90 in the browser and press the Add rows button b. Select the three analyses AnaReg_14x10_D0. Select all the segments for the risers from the 3D window. Select Ana_template as the Structural analysis b. Capacity check specification: DNV OS-F201. open the file Read_Combined_loading. Press OK. Approach=LRFD Limit State=ULS and Functional load group = 2 Safety Class=Normal c. a. 22. (Remember to press the segment selection button and use LMB to select. Analysis time window: Select Limit time interval and Number of periods. Press the Name column header to auto fill names. Create a combined loading analysis template and name it CL_template: RMB | New Combined Loading Analysis … on folder Capacity/Combined Loading Analysis. Open the multiple combined loading analyses dialog: RMB | Multiple Analysis … on folder Capacity/Combined Loading Analysis. 26. View the combined loading contour plot in the 3D window: RMB | View Result Component … | Sample extreme on item Capacity/Combined Loading/CL_AnaReg_14x10_D0 You may switch between the different analysis by RMB | Set current … 27. Repeat step a-c. Press the Edit button for the CL_template row and modify the capacity check setting to ISO 13628-7 and Design factor = 1. Press the Start button to run the analyses.0.c. 23. d. 25. 28. Set the display configuration to Combined Loading Result. When the analyses have completed you may view log files by doing RMB on each analysis in the activity monitor dialog. Press OK. Save and close the workspace. 34 . e. Open the combined loading Activity Monitor dialog: Select all analyses to be executed in the browser and do RMB | Run Combined Loading Analysis … 24. Go to the folder Results/Combined Loading Results/Utilization Factor and plot the utilization factor for riser1 and riser3 along the lines: Select the result objects and do RMB | Plot utilization factor. Press Apply to generate new combined loading analyses with settings from the template.