Home

SHIPX Vessel Responses (VERES)

1. Check In ag Check In amp Close Figure 4 14 The Vessel Response calculation main dialog window 3 You can now select result files by clicking the Add New Result button not necessary for the first file as a default entry 1s always created at startup To access a SHIPX Run the checkmark in the Get file by run column in the result list should be present and you can click a button to the right in the cell The dialog box seen in Figure 4 15 appears P 2004 12 21 SHIPX Vessel Responses Users Manual 4 15 MARI NTEK Hands on Introduction to VERES Locate Vessel Response Run Step 1 Select ship 2175 mgf imported Step 2 Select loading condition na U OWL Design waterline T 3 50 m Step 3 Select valid run 5 175 Demo Calculation File name fram run Figure 4 15 Locate Vessel Response Run dialog 4 To locate a Vessel Response Calculation simply select the ship loading condition and run in the dialog box and click OK There must be a valid result file present i e a full calculation must have been performed in order to be able to select a run In this example we will select the demo calculation from Section 4 2 5 Give the calculation a label by entering S 175 in the Label cell This abel is used as part of the legend text on the plots 6 When a result file is defined you can use the buttons on the top of the main dialog see Figure 4 14 u Transfer functions Stati
2. ri p LSB EZ rm BE MES LU JULI WALL EEE AL LLLLLELLLLLLLLLLLI 5 amp 7 B 8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 PEAK PERIOD Tp sec Figure 2 2Operability limiting boundaries 227 Time domain calculations The abilitv to perform time domain calculations is also available in VERES In the time domain calculations the linear hvdrodvnamic coefficients of the ship hull can be combined with non linear wave excitation forces and restoring forces as well as non linear effects from motion control svstems P 2004 12 21 SHIPX Vessel Responses User s Manual 27 MARI NTEK Introduction WI LINY IJ WI Linear rigid body response in heave m l l Ri li 1230 1240 1250 1260 1270 1280 1290 1300 1310 Time sec 77 Linear rigid body response in heave BIE 2 130J0E 01 m Total rigid body response in heave PHE 2 24765H 01 im Figure 2 3 Time domain simulations linear and non linear heave responses 2 5 NEW IN VERSION 4 0 In Version 4 0 of VERES the integration towards SHIPX 15 taken one step further and the input coordinate system as well as error messages and output has been adapted to the definitions in SHIPX This means that all user input 1s now related to a coordinate system with the x axis pointing forwards from the aft perprndicular AP the z axis 1s
3. min 2 i 1 2 3 9 6 63 Jazi e Jazi Sa W dw pog PR NEPA 6 64 where isthe RMS value of the limiting vertical acceleration tabulated in Table 6 5 gai 15 the RMS value of the vertical acceleration per meter significant wave height in the ith interval Saz 0 is the response spectrum for the vertical acceleration P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 33 Oi 4 4 i S1 do 0 lim lim O Cj Ou Figure 6 11 Dividing the response spectrum Saz 0 corresponding to the ISO frequency intervals lim Oi 1 1 9 and integrating to find the RMS value of the interval If a two parameter JONSWAP spectrum 15 applied 1 the statistical respose 15 not linear with respect to H an iteration is performed to ensure that g 15 calculated with correct H and y value Otherwise a unit wave height 1s applied Table 6 5 Numerical values of severe discomfort boundaries for vertical acc 18 Frequency Hz Acceleration m s centre frequency of Exposure times one third octave 8h tentative band Forces in body fixed coordinate system lim due to criteria regarding the acceleration forces in the body fixed coordinate system i e LON LFE and VFE is calculated directly from the results of the short term statistics The short term statistical value of the response per meter wave height Ofrc H is know
4. 3 1 327 Daae C 21 3 1 THE SHIPX WORKBENCH 3 2 33 SHIPX WORKBENCH UTILITIES 3 12 ILL USEF INAI AC sonet 3 3 3 1 Report viewer 5 12 3 1 2 Plug Ins NOE 3 3 3 3 2 Process Manager 3 13 3 3 Using the Database Browser 3 4 RENO 3 13 3 1 4 Standard SHIPX dialog buttons 3 5 3 3 4 Automatic Update 3 13 3 2 THESHIPX DATABASE 3 7 3 3 5 Program Obptions 3 15 PM EE UU em 3 7 34 HULL GEOMETRY MANIPULATION 3 16 MER Ur del 3 4 1 Edit 3 16 DD Hul 3 3 4 Hull transformation 3 17 3 2 4 Loading conditions 39 35 SHIPXPLUG INS ce 3 18 2 la ie ein 3 10 P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK s 31 THE SHIPX WORKBENCH 3 1 1 User Interface 3 2 The SHIPX Workbench represents the visible part of SHIPX Workbench Environment interactions with the user are through this part of the program Together with SHIPX Workbench there is a framework that can be used to extend the workbench with new functionality through so called Plug Ins This can be everything from a complete new calculation module for instance a manoeuvring program to a new menu option File Database Edit New View Tools Plug Ins Window Help a mm es x e A Hi 12 54 16 76 R q Responses in Wav
5. might contain both nput and Results and these can in turns contain single values tables with values or tables with objects In addition information like date and time describing text and version number for the data 15 stored in a run Right clicking on Runs in the Database Browser produces a context menu where the user can create new runs of various kinds depending on the presently available plug ins in SHIPX The files associated to each run can be accessed most easily by selecting Explore from the right click menu of the Results or Input items That opens a Microsoft Explorer window in the correct directory of the SHIPX file structure A run can be deleted duplicated copied to the same loading condition copied and moved to other ships loading conditions P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK six 3 11 3 2 6 Common Settings In addition to store ship hulls loading conditions results etc it 1s possible to save a set of common settings default values for things like water density temperature preferred units for speed trim etc Edit Common Settings 1s located on the Edit menu Eg Common settings i 4 Sea water density 1 025 tenet Sea water salinity 3 50 Sea water temperature 15 00 C Tank water density 1 000 terre t Tank water temperature 16 50 Shell plating thickness 2 mm Shell plating in of displacement 0 40 Default speed unit knot
6. 8 Back in the Transfer function Statistics dialog select as the new motion point by pulling down the menu in the Motion Point pull down menu S For linear frequency domain calculations the mean value of the response is zero and the standard deviation will be equal to the Root Mean Square value RMS P 2004 12 21 SHIPX Vessel Responses Users Manual 4 93 MARI NTEK Hands on Introduction to VERES 9 Plot the results by clicking the Plot Data button The plot should now look like Figure 4 23 ACCELERATIONS Position FP std dev HEAWE ACC g force WE B 7 8 g 10 11 12 13 14 15 PEAK PERIOD Tp sec M 5 175 s lz 0 0kn 0 07 B S IT75 lz 0 0kn 30 0 SE SE 25 175 lz 00kn 60 0 Project 5 175 Dema Wave spectrum Pierson Moskowit Hs 4 00 m Long crested seas Figure 4 23 Standard deviation of vertical accelerations in the bow for the S 175 hull Figure 4 23 shows the standard deviation of the vertical accelerations at the bow for a Pierson Moskowitz wave spectrum with significant wave height Hs 4 0 m The results will change depending on the peak period Tp and each combination of Hs and Tp describes the sea state completely If the sea state is modeled by the Pierson Moskowitz wave spectrum or the JONSWAP Hs Ir v spectrum the standard deviation will be proportional with Hs For the JONSWAP Hs Tp wave spectrum and Torsethaugen wave spectra this will not be the case since the p
7. If you wish to move your database to another location make sure no users are using the database and move the top level folder with all its subfolders to a new location Afterwards the database can be opened from the FilelOpen Database menu option P 2004 12 21 SHIPX Vessel Responses User s Manual 3 12 MARINTEK s 3 3 SHIPX WORKBENCH UTILITIES 3 3 1 Report viewer The report viewer in SHIPX is a stand alone application which SHIPX can communicate with directly Features of the SHIPX Plot Program include simple ASCII data files Plotting of X Y scatter plots Histograms Contour plots Polar plots Formatted text reports Direct export to Microsoft Word Using Acrobat PDF Writer the reports can be exported directly to PDF U U U U U U U U U yy MARINER Company logo in plot header see Section 1 4 page 1 5 for details SHIP RESISTANCE SHIP PESISTANCE AND EFFECTIVE POWER 2002 02 18 HELL MODEL Hu H2553A Model Seale 25 511 Loading condition 1 Trial Draught AP TP 8 023 amp 023 HULL MODEL Mii NI25523A Fytnbal Unie SHIF H DEL Length Bary ler I 262 900 10 9832 Largth cn wstesrline lu xl 273 888 10 904 Hzandth wmtmzlirim Eu 32 200 1 282 Dzaught at Lyt T 8 023 0 320 lietted zurtacs 2 10546 00 16 725 Wetted z rt of transos stern Az x7 5 87 0 016 Transv proj area WI Pij x 1770 00 0 575 Velume displacement Y x7 44024 57
8. In addition to the standard sea spectra the VERES Postprocessor includes the option to import a user defined wave spectrum for a specific seastate from file This enables e g comparisons between model or full scale tests and calculations applying the same measured wave spectrum The file format 15 presented in Appendix 7 2 2 page 7 13 Unidirectional spectra as well as short crested spectra are included in this option Since the user defined spectrum only defines one sea state some of the postprocessor options are not available when this option 1s chosen In addition to the Torsethaugen wave spectrum to represent two peaked spectra one can also combine two JONSWAP spectra when calculating short term statistics The JONSWAP two peaked spectrum is simply a summation of two JONSWAP wave spectra where the swell component can be explicitly defined as opposed to the Torsethaugen formulation The options for the two peaked JONSWAP spectra are the same as for the Torsethaugen spectrum i e the swell component can either have the same long or shortcrestedness as the wind component or one can choose to have a long crested swell component with either constant offset direction from the wind direction or a constant offset direction relative to the ship Hint If you want to plot the spectrum shape for a specified wave spectrum in the VERES Postprocessor then select the Combinations of Hs and Tp option in the Specify Wave Spectrum Dialog Ther
9. where Zs is the Pierson Moskowitz form of the wave spectrum and y is the JONSWAP peak enhancement factor f 1s the nondimensional frequency f In f 6 25 where fpis the peak frequencv p 6 26 EN exp RZ sj 6 27 vel f Pl sez 1 6 28 Here the parameter o 0 07 for f lt 1 and 0 09 for fn 2 1 The normalizing factor related to be the P M form 15 C E COM CES 6 29 70 MM mE ed where is the gamma function N represents the frequency exponent for the high frequency range of the spectrum and is found to be in the range 4 to 5 The factor M may usually be given a value 4 A is a function of y N and M and is found numerically by integration of the spectra for different values of N and M Regression analyses shows that 4 can be approximated by Ay 1 M In y fa N M 2 6 3 0 for a wide range of N and M The functions fi and f are found as RA M a M N b M 9D 6 31 f N M N9UD e M 6 32 The parameters a c are found to be well represented by lq M 6 33 UM UM 3 6 34 c M 1 45M 0 96 6 35 do M 2 3M 0 57 6 36 0 58M9 0 53 6 37 6 38 co M 1 04M 0 94 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 12 MARI NTE Postprocessor Reference 6 2 2 Short crested seas In reality long crested seas are rarely encountered at sea A certain wave spreading 1s more
10. If a relative motion calibration file xmc is specified for the motion point in question the relative motion transfer functions will be calibrated before calculating any statistical values See Section 6 1 4 page 6 4 for details P 2004 12 21 SHIPX Vessel Responses Users Manual 6 46 MARI NTE Postprocessor Reference P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Appendix 7 APPENDIX 7 1 This chapter will provide information regarding file formats that may be useful for the end user In particular the import export file formats described in Section 7 2 may be useful for the common uscr Contents 4 APPENDIX ii 7 1 7 1 OUTPUT FILE FORMATS 7 2 7 1 1 Motion transfer functions rel 2 7 1 2 Global wave induced loads re3 7 4 7 1 3 Generalized transfer functions BI tr JEZ 7 1 4 Dynamic pressure distribution re 7 9 P 2004 12 21 7 2 IMPORT EXPORT FILE FORMATS 7 12 7 2 1 Mass distribution files 7 2 2 Wave scatter diagram files Lu 7 2 5 Wave spectrum files wsp 7 14 7 2 4 Relative motion calibration file rmc 7 15 7 3 DIMENSIONS AND CONSTANTS Tel SHIPX Vessel Responses Users Manual 72 MARI NTEK Appendix 7 1 OUTPUT FILE FORMATS 7 1 1 Motion transfer functions rel This section describes the file that contains data of predicted motions from the VERES program The forma
11. SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES Main dimensions from input Length between perpendicularz rol 175 000 Breadth 25 400 Draught midship Iri 9 500 ainkadge rol a 000 Trim aft 0 900 Hull data from geometry Hull sections le x Hull length tr 175 000 Hull breadth at mid section rol 25 400 Hull draught at mid section iri 3 500 Coefficients for data check etc Type Specified Calculated Displacement tonnes 3509 57 23509 47 Vertical center of bouyancy KE Sees Vertical center of gravity YEG 9 550 Longitudinal center of bouyancy LEE o23 9438 Longitudinal center of gravity LCG 64 950 64 945 Block coefficient ch 0 5 0 568 Water plane area coefficient TT 0 705 D Prismatic coefficient Cn O 566 Mid section area coefficient In 0 2957 O 966 Longitudinal metacentric height 204 603 Transverse metacentric height GMt Roll radius of gyration r44 B 331 Pitch radius of gyration EL 42 000 Yaw radius of gyration r5b5 42 000 Roll yaw radius of gyration ri O 000 Applied in the hydrodynamic calculations Figure 4 9 Example of a data check report P 2004 12 21 SHIPX Vessel Responses Users Manual 4 10 MARI NTEK Hands on Introduction to VERES 4 2 7 Viscous roll damping For the roll motions of a conventional ship viscous effects are important since the potential damping is low
12. Vert acc bridge 32 Ukn k Slamming 3 32 0kn Green Water 7 32 0kn ISO 2041 hours 3z2 lkn Na waves above this curve Figure 6 10 Operability limiting boundaries including the theoretical limit of breaking waves Figure 6 10 shows an example of operability limiting boundary curves where the ISO criterion for motion sickness at the bridge 1s the limiting criterion Please note that the limiting significant wave heights are calculated up to a user specified maximum value 18 m in Figure 6 10 Exceeding limiting wave heights are set to the specified value 22 The user specified maximum value is introduced to avoid infinite limits A typical example is a roll motion criterion which will give infinite limiting significant wave height in head seas since no rolling motion exist for this wave heading P 2004 12 21 SHIPX Vessel Responses Users Manual 6 30 MARI NTE Postprocessor Reference There are combinations of wave heights and wave periods that cannot exist because the waves would be too steep to be stable 1 e they break before reaching the combination The theoretical limit of breaking waves may be plotted together with the operability boundary limits the thick solid line in Figure 6 10 The breaking wave height H is found by 6 57 as a function of the peak period Tp 5 br 2 A T 0 1057 6 57 The operability limiting boundaries can either be plotted for eac
13. 0 8564 l l Project 5 175 Demo Morth sea area 11 Annual Wave spectrum Fierson Moskowitz Long crested seas All headings equal prob af occurence Figure 4 26 Long term statistics for the vertical accelerations at FP for the S 175 hull P 2004 12 21 4 25 SHIPX Vessel Responses Users Manual 4 26 MARI NTEK Hands on Introduction to VERES 4 3 5 Operability limiting boundaries An example of operability limiting boundary curves 1s shown in Figure 4 31 Different seakeeping criteria appear as limiting curves in a diagram with the limiting significant wave height as the ordinate and with the characteristic wave period along the abscissa In addition the theoretical limit of breaking waves may be plotted in the diagram The vessel meets the seakeeping criteria for the wave height wave period combinations below all the boundary curves For further details on the seakeeping criteria and operabilitv limit boundaries please refer to Sections 6 4 1 and 6 4 2 To obtain the operability limits results presented here you have to go through the short term statistics example or add the motion point specified there and then perform the following steps 1 In the Transfer function Statistics dialog click the Define points positions button to enter the Specify Points Positions dialog We want to specify three more motion points FP at base line Deck at bow and Bridge Make sure that All point labels is selected in the View box
14. Derived Parameters New length overall Loa 27 30 m Increments New moulded depth 0 10 00 m Cp 0 001 New breadth overall Boa Bmax 300 m LCB 0 005 of Lpp New stern position Aft 1 40 m Figure 3 13 Hull Transformation Tool P 2004 12 21 SHIPX Vessel Responses User s Manual 3 18 MARINTEK s 3 5 SHIPX PLUG INS Table 3 1 Available SHIPX Plug Ins Plug In Function Basic Optional XIS Link Connecting the workbench to the SHIPX database Works as a link between the Plug Ins and the database Hull Manipulation Hull manipulation module add change delete stations contour lines and 3 D lines as well as geometric scaling Graphical presentation of the hull lines in 2D 3D File import export Import of hull geometry from various formats filters e VERES file format MGF AutoShip DRA AutoHydro GF AutoCAD DXF ShipShape LIN projects NAPA files exported with a special NAPA macro available from MARINTEK N2X Export to VERES REP inne 77777 operation project files Waveres Calculation of wave resistance Animation Lab Animation of ship motions and sea state structures peer sy MARINTEK laboratories internal tool only Ship Speed amp Speed prediction tool including resistance and Powering propulsion in calm water as well as prediction of speed loss in waves due to ad
15. Short term stat t Long term stat Select All Sel special Unzelect All Figure 4 17 The Transfer function Statistics dialog For short waves the responses are small while for long waves the ship motions are dominated by hydrostatic effects For the head sea case there 15 a domain around 9 seconds where the heave motion 1s almost cancelled This phenomenon corresponds to a wavelength almost equal to the length of the ship giving small hydrodynamic forces due to cancelation along the hull It should be noted in Figure 4 19 roll motion that the number of wave periods close to the resonant period is insufficient This can be seen both at 30 and 60 wave heading where the resolution close to the resonant peak in the transfer function is poor P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES DISPLACEMENTS UE UE SEN CZ AR RAO HEAVE eta 3 A EHE KAN SF aU a a aM JU 10 11 12 13 14 15 16 17 18 19 20 21 22 Z3 24 25 25 WAVE PERIOD sec WW 5 175 lzZ 0kn 0 0 _ 5 175 12 00kn 30 0 5 175 l 00kn 60 0 Project 8 175 Dema Figure 4 16 Heave motion characteristics of the S 175 hull P 2004 12 21 4 18 SHIPX Vessel Responses Users Manual 4 19 Hands on Introduction to VERES DISPLACEMENTS 17 16 15 14 13 12 ES cu qi 10 A g m
16. and simply type the names of the motion points in the Description text box and click Add after each Specify Points Positions Al point labels File label t One paint for all files 5 175 WERES Fostpracessor Edit point properties Position on the hull A 1 75 000 m fad of AP i aoo o m aff center pos starboard E H2000 m above Base Line Slamming properties k factor 0000 Threshold velocity werit 0000 m sec Threshold pressure 0000 kPa Relative motion calibration file 358 Madify Copy from Point properties File peint position Y positian Z pozitiori epar 0 00 z 0 00 Wer LE FP at base line Bridge Deck at how Relative Motion Report Number of points Figure 4 27 The Specify Motion Points dialog 2 Select All points for one file in the View box Boxes for specifying the coordinates now appear in the Edit Motion Point box Specify the coordinates x y 2 175 0 0 0 0 0 m for FP at base line x y z 47 5 3 0 32 0 m for Bridge and x y z 175 0 0 0 10 These motion point coordinates are not the correct positions of the bridge on the S 175 vessel but are selected to provide values for this example P 2004 12 21 MARINTEK SHIPX Vessel Responses Users Manual Hands on Introduction to VERES 4 27 20 0 m for Deck at bow Click the Modify button after each The Specify Poi
17. environment box Click the Specify button to enter the Long term statistics dialog see Figure 4 24 In the Open Scatter Data File box click the Open button and choose a11an sea This file is located in the c Program Files SHIPX PlugIns VERES Examples folder Select View to have look at the scatter diagram in a text editor Select Sum over all headings equal probability of occurence in the Wave Headings box and press OK to return to the Transfer function Statistics dialog Click the Spectrum button to enter the Select spectrum type dialog see Figure 4 25 Select the Pierson Moskowitz spectrum Pierson Moskowitz JONSWAP and Torsethaugen wave spectra are available and click OK See Section 6 2 1 p 6 6 for details on the wave spectra P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES Select spectrum type Wave Spectrum Pierson Mozkowitz Wave spreading Long crested seat Figure 4 25 The Select spectrum type dialog Cancel 5 Click the Plot Data button The results should now look like Figure 4 26 PROBABILITY OF Ex CEEDANCE ACCELERATIONE Position 1 0 10 10 1 0 10 09 1 0 10 08 1 0 10 07 1 0 10 06 1 0 10 05 1 0 10 0 1 0 0 03 1 01002 004705 0e U7 AT hala LE LB HEAVE ACC g force 5 175 lz 0kEn T R 2 45 s Weibull slope h
18. m 4 8 1 C 7 C H EN LLLLLLLELLLLLEELLLLLLL TITITITIIIIIIIIELHLIIITT 2 PET TT TTT ET Ed EEN ldem TT 0 al d m 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 WAVE PERIOD sec 5 175 lZz kn 0 0 5 176 12 00kn 30 0 E A 5 175 l 00kn 60 0 Project 8 175 Dema Figure 4 19 Roll motion characteristics of the S 175 hull P 2004 12 21 MARINTEK SHIPX Vessel Responses Users Manual Hands on Introduction to VERES DISPLACEMENTS Et TT me PE EE EE ee LLL RAO PITCH 5 deg m 8 175 S 175 10 11 12 13 14 15 16 17 18 19 20 21 22 Z3 24 25 26 WAVE PERIOD sec lzZ 0kn 0 0 E 35 175 lz 0kn 60 0 Project 8 175 Dema Figure 4 20 Pitch motion characteristics of the S 175 hull P 2004 12 21 124 00kn 30 0 4 20 SHIPX Vessel Responses Users Manual 4 21 MARI NTEK Hands on Introduction to VERES 4 3 3 Short term statistics Now we will show the calculations of short term statistics for the vertical accelerations in the bow The theory 15 given in Chapter 6 2 and the results of the calculations are presented as the standard deviation of the vertical acceleration as a function of the peak period in Figure 4 23 To obtain these results you have to perform the following steps 1 In the Transfer functions Statistics dialog select Accelerations in the Options Study pull down menu 2 Cli
19. s a y2 AM ra Ap M V M M fu i where 7 r z AM V LB at fo 5 1 5 2 5 3 5 4 where the coordinates x and 2 are given relative to the center of gravity in a coordinate system similar to the input coordinate system ref Section 5 3 1 AM is the weight of an item located at x z and M is the total weight of the vessel P 2004 12 21 SHIPX Vessel Responses Users Manual 58 MARI NTE Postprocessor Reference 54 EQUATIONS OF MOTION VERES 1s based on inear strip theory The basic assumptions of the linear theory are a The wave amplitudes are small compared to some characteristic dimension of the vessel The resulting motions will then be proportionally small a The wave steepness is small 1 e the waves are far from breaking In linear theory the wave loads and motions are linearly proportional to the wave amplitude As a consequence of this we can obtain results 1n irregular waves simply by adding together results from regular waves of different amplitudes wavelengths and propagation directions To simplify the problem further steady state conditions are assumed 1 e there are no transient effects present due to initial conditions This implies that the linear dynamic loads on the body are harmonically oscillating with the same frequency as the wave loads that excite the body i e the frequency of encounter and thus allows us to perform our computations in the fr
20. u Related documents u Details o Principal characteristics o Model scale characteristics o Hull geometry o Laghtship weight o Arrangement o Related Documents Ship data like geometry main dimensions and loading condition data are as much as possible stored the database according to the ISO STEP standard e g AP 216 for ship moulded forms From the SHIPX Workbench including the Database Browser the data are seen through facade objects 1 order to make them more easily to read and access A number of functions can be activated by right clicking on the ship in the Database Browser Figure 3 5 shows the context menu a Edit Hull gives access to the hull manipulation features in SHIPX where you can modify the hull geometry manually by editing each individual point describing stations contour P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK six 3 8 lines and 3d lines as well as adding or deleting hull geometry elements This feature 15 described in Section 3 4 1 a Hull Transformation gives access to the hull transformation features in SHIPX described in more detail in Section 3 4 2 u Principal characteristics can be modified by Edit Principal Characteristics in the context menu a Edit Ship Model Characteristics gives the opportunity to define model scale ship type selected from a list as well as defining text strings to describe appendix type of turbulence simulator and possible other comments to
21. 02 2002 13 59 57 3 01 0195 22 11 2001 12 30 35 18 02 2002 13 06 10 13 12 2001 17 20 49 09 01 2002 22 41 10 09 01 2002 22 27 24 EE END 330 0 KB 749 0 KB 4240KB ted b 2961 0KB 516 0 KB 95 0 3 0 KB 307 0 KB 2860KB Cancel Update information Time to download at 56 Kbps 15 min 1 sec E Total download size 6 31 MB Figure 1 6 SuiPX Auto Update Utilitiy After all the files are installed and updated the SHIPX Workbench 15 ready for use and can be started via the Start menu P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK Program Installation I gt 1 3 HASP DEVICE DRIVER If some of your Plug Ins require a harware key in order to function properly e g SHIPX Vessel Responses you will need to install the appropriate driver for the HASP key The HASP Driver installation program can be downloaded from the SHIPX website If you are installing from a CD it will be avaliable from the startup screen see Figure 1 1 1 4 COMPANY LOGO IN THE SHIPX PLOT PROGRAM The SHIPX Plot Program can be customized with your own company logo in the plot report header To get your company logo in the upper left corner of all plots reports as the MARINTEK logo shown in Figure 3 8 simply place a file containing your logo in the AProgram FilesNSHIPXNbin folder The following rules apply 6 The logo file must have the name logo lt ext gt where ext 15 the f
22. 2 785 Bleek efti iant l 1 0 625 0 625 itk 1 0840 Zorralation cnaE 107 zzBH GE as 107 0 1239 Heawatec temp E 15 0 ka 5 E f d Mr Wi Fa Ez Tai Trim Sines m knots m s Id 1 RH KH 1 ies AF FE E zz a eE fr id DD 1 830 0 179 BIE 73 740 1 137 81 0 03 0 113 n 213 19 00 1 951 0 388 360 40 5389 2 124 14 D D 5 D i2 amp 0 240 20 00 2 055 0 192 L25 1 1218 55 D cum n 140 U 2Tr 2l gg 2 156 0 200 1223 zH 11384 D0 135 20 0 005 n 155 n 115 22 00 5 259 0 288 ijti ia 15538 1 114 50 0 041 D i amp 0 356 23 00 2 341 0 228 1545 70 12501 0 1212 97 0 0144 0 1 4 tE 24 00 2 489 0 2308 1732 53 Al1452 D 102 44 0 047 D 1 0D lt 1E 25 00 2 367 0 248 12717 45 4517 7 105 56 0 05 D 213 0 5 28 00 2 499 0 258 2142 54 26557 7 WHE 0 0584 D 222 0 93 Ship speed kraja Pa datapoints 1 i Pio iatkpeinbi Figure 3 5 Example plots and reports from the SHIPX Plot Program A full description of the supported file formats can be found in the SHIPX Plot Program online help P 2004 12 21 SHIPX Vessel Responses User s Manual 3 13 MARINTEK s 3 3 2 Process Manager To be able to serve as a workbench for computationally intensive applications SHIPX has a built in Process Manager where all computations show up Figure 3 9 shows a screen shot of the Process Manager The start time percenta
23. 42 5 3 D REM ifm iseven 6 43 Fes 7 1 1 2vmaz Further m is the wave spreading index m 0 represents a uniform spreading with equal contributions to the wave energy from all directions As 1s increased the energy becomes increasingly concentrated about the primary wave direction see Figure 6 3 Thus a nearly long crested sea state can be obtained by choosing a small wave spreading angle v and a high value of m For ship design purposes the most common practice is to use m 2 and Ving 90 This cosine squared spreading 15 apropriate for typically occurring conditions in the open ocean However spreading angles as low as 60 or as high as 120 may frequently be found Lloyd 20 Figure P 2004 12 21 SHIPX Vessel Responses Users Manual 6 13 MARI NTE Postprocessor Reference 6 4 shows a directional cosine squared spectrum for discrete heading intervals of 15 and V pax 90 Relative wave heading deg Figure 6 3 Wave energy spreading function D cosm v for different values of m as a function of the relative heading v If wave headings from 0 to 180 are used in the calculations of the transferfunctions in VERES the postprocessor will try to apply symmetry properties to obtain transfer functions for waves from the opposite side of the hull centerplane This can be done for the motion transfer functions since these are calculated at the centerplane In addition glob
24. 6 3 2 Operational profile 6 23 OF OPPRABIELI 6 24 6 4 1 Seakeeping criteria 6 25 6 4 2 Operability limiting boundaries 6 29 6 4 5 Operability diagram 6 55 6 4 4 Percentage operability 6 36 6 5 FATIGUE ASSESSMENT 6 39 6 5 1 Introduction 6 59 P 2004 12 21 SN CUIVES esito eie dis 6 39 6 5 3 Fatigue damage 6 40 GO STONING rae Roc 6 42 6 6 1 Slamming pressures 6 42 6 6 2 Short term statistics 6 45 6 6 5 Long term statistics 6 44 6 6 4 Summary of input 6 45 SHIPX Vessel Responses Users Manual 62 MARI NTE Postprocessor Reference 6 1 RESPONSES IN REGULAR WAVES This chapter describes some definitions concerning the responses in regular waves as a reference when using the Postprocessor Some of the definitions here are already defined earlier in the text but they are briefly summarized here to give a quick reference 6 1 1 Transfer functions The ratio of the response per amplitude of excitation 1s known as the transfer function Physically it is the complex amplitude of e g the vessel motion or a global load in response to an incident wave of unit amplitude with frequency and direction f The wave elevation at the origin 1 e at LCG 1s defined as Ca cos uwt 6 1 and the motion transfer functions are defined
25. Dep of Naval Arch University of Osaka Prefecture 1978 IKEDA Y ET AL On roll damping force of ship effect of friction of hull and normal force on bilge keels Technical Report 00401 Dep of Naval Arch University of Osaka Prefecture 1978 IKEDA Y ET AL On roll damping force of ship effect of hull surface pressure created by bilge keels Technical Report 00402 Dep of Naval Arch University of Osaka Prefecture 1978 International Organization for Standardization International Standard ISO 2631 3 Evaluation of human exposure to whole body vibration Part 3 Evaluation of exposure to whole body Z axis vertical vibration in the frequency range 0 1 to 0 63 Hz 1985 KATO H On the frictional resistance to the rolling of ships Journal of Zosen Kiokai 102 115 1958 LLOYD A RJ M SEAKEEPING Ship Behaviour in Rough Weather Ellis Horwood Limited 1989 MCCAULEY M E ROYAL J W WYLIE C D O HANLON J F AND MACKIE Motion sickness incidence Exploratory studies of habituation pitch and roll and the refinement of a mathematical model Technical Report 1733 2 Human Factors Research Inc Goleta California April 1976 MILNE THOMSON L M Theoretical Hydrodynamics MacMilan Co New York fifth edition 1968 NORDFORSK Assessment of ship performance in a seaway 1987 OcHI M K Prediction of occurrence and severity of ship slamming at sea In Fifth Symp on Naval Hydrodynamics pp 545 96 Washi
26. Hull transformation SHIPX PLUG INS HANDS ON INTRODUCTION TO VERES 4 4 2 4 2 1 4 2 2 d 4 2 4 4 2 5 4 2 6 4 2 7 4 2 8 4 2 9 OUTLINE CALCULATING VESSEL RESPONSES IN WAVES Importing the hull lines and define loading condition Defining a Vessel Response calculation Run Defining the vessel geometry Selecting calculation method Vessel description input Running a data check Viscous roll damping Condition information Running the computations 4 3 POSTPROCESSOR TUTORIAL 4 3 1 4 3 2 4 3 3 4 3 4 4 3 5 4 3 6 Preparing the data for postprocessing Responses in regular waves Short term statistics Long term statistics Operability limiting boundaries Percentage operability MAIN PROGRAM REFERENCE 5 BASIC ASSUMPTIONS 52 DEFINITION OF COORDINATE SYSTEMS WAVE HEADING AND MOTIONS 5 3 VESSEL DESCRIPTION 5 3 1 2305 2 RIA 5 3 4 2 9 Coordinate system for the geometry file Partitioning of the hull into strips Description of sections Geometry file Radii of gyration 5 4 EQUATIONS OF MOTION 5 5 VISCOUS ROLL DAMPING 5 5 1 Frictional roll damping 552 Eddy damping 5 5 3 Bilge keel damping 5 6 GLOBAL WAVE INDUCED LOADS 5 6 1 Introduction 3 6 2 Outline of theory 3 6 3 Input Description POSTPROCESSOR REFERENCE 6 1 RESPONSES IN REGULAR WAVES P 2004 12 21 vi 3 13 3 13 3 13 3 15 5 16 SHIPX Vessel Responses MARI NTEK Users Manual 8 6 1 1 Transfer functions 6 1 2 Definition
27. INSTALLATION This section will describe the different steps required to get your SHIPX Workbench with licensed Plug Ins running on your PC The rest of the chapter will describe in more detail the functionality of SHIPX and gives an introduction to the most common functions in the workbench Please follow the instructions carefully The use and further set up of SHIPX 15 described in Chapter 3 1 1 INSTALLATION INSTRUCTIONS To install SHIPX you can either run the installation from CD or download the latest available from the Internet the SHIPX website is located at http shipx marintek sintef no If downloading it from the Internet you will be prompted for a user name and password that you should have received from MARINTEK When downloading from the Internet you will need to unzip the program installation to a temporary folder and start the setup exe file If you are installing from a CD the startup screen will help you accessing the different installation programs see Figure 1 1 Weis ae ShipX Workbench Install ShipX View ShipX User s Manual Install Acrobat Reader Install HASP Device Driver Exit a Www sintef ma IN SINTEF Figure 1 1 The installation startup screen when installing from a CD P 2004 12 21 SHIPX Vessel Responses Users Manual 12 MARI NTEK Program Installation The installation program installs the SHIPX Workbench with its necessary components such as the appropriate version of t
28. If selected VERES may take viscous effects into account by empirical formulas For further reference see section 4 4 When the encounter frequency is close to the resonant frequency the damping will be of major importance for the response level VERES may give unrealistic roll motions if viscous roll damping is not included To include viscous roll damping the following steps are needed l Step into the Roll Damping and Motion Control dialog by clicking the Roll Damping etc button in the Edit Input part of the main dialog To include viscous roll damping simply check the nclude viscous roll damping check box If viscous roll damping is selected a wave amplitude must be specified since some of the viscous effects are non linear with respect to the wave amplitude If you plan to perform short term statistics calculations later the wave amplitude should preferably be chosen with respect to the significant wave height e g by using the mean value of the wave heights you wish to use when calculating the short term statistics The next step 1s to describe the bilge keels 1f any Select bilge keels to be included by checking the check box and by clicking the Specify button you enter the Bilge keel description dialog Figure 4 10 The bilge keels are specified by defining the breadth and position at each section defined in the geometry file The position 1s defined as the intersection between the bilge keels and the hull This
29. NTE Postprocessor Reference 6 35 6 4 3 Operabilitv diagram The VERES Postprocessor can present the operability contours of a ship for different speeds and headings for a given sea state in an operability diagram The operability diagram shows the combinations of vessel speeds and headings where the criterion criteria are exceeded as shaded red areas in a plot with the vessel speed on the y axis and heading on the x axis Demo Vessel Hs 4 0 m Tp 10 00 sec All the criteria Ship s speed knots All the criteria Exceeded Not exceeded Project Demo Project Wave spectrum Pierson Moskowit Lorid crested seas Figure 6 12 Example operability diagram Figure 6 12 shows the operability diagram for a container vessel with active roll stabilizing fins The major contribution to the reduced operability at beam and following seas is due to large roll motions The efficiency of these fins increase with higher ship speeds Hence no criteria are exceeded at full speed P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE Postprocessor Reference 6 36 6 4 4 Percentage operability The percentage operability expresses the percentage of the time period under consideration where the vessel is able to satisfy the seakeeping criteria Figure 6 13 shows how the percentage operability is presented in the SHIPX Plot program The percentage operability is obtained by combining the operability limiting boundaries with the probab
30. O7 LIFT LLL LLL A sale bnie i s Ge 85 dh JB ds 16 19 18 da 20 PEAK PERIOD Tp sec W MIL EU A C RZE O RJ AA A c Cu sign wave height Hs m h V acc at FP 0 154 12 0kn Slamming 3 lz En a 1 Green Water 7 lz Ekn 4 ISO hours lz Ekn Mo waves above this curve Figure 4 31 Operability limiting boundary curves and the theoretical limit of breaking waves for the S 175 hull in head seas The results show that the vertical acceleration at FP 1s the critical criterion in head seas 0 wave heading The limiting significant wave height is about 4 5 m The theoretical limit of breaking waves indicates the limit combinations of Hs and Tp where the waves are becoming too steep to be stable Above this limit there should theoretically not exist waves see Chapter 6 4 for further discussion P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 30 4 3 6 Percentage operability As a last example let us calculate the percentage operability of the vessel for the same criteria as in the operability limits example Each criterion is presented seperately summed over all wave headings The same scatter diagram as in the long term statistics example is used The theory 15 given in Section 6 4 4 p 6 36 To obtain the results in Figure 4 32 you must first d
31. and 4 hours are frequently used in the litterature Figure 6 6 shows the MSI as a function of frequency and vertical acceleration level for a 2 hour exposure time lt ra o MOTION SICKNESS INCIDENCE 1 e Figure 6 6 Motion Sickness Incidence MSI as a function of frequency and acceleration for 2 hour exposures to vertical sinusoidal motion from McCauley et al 21 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 19 MARI NTE Postprocessor Reference 6 3 LONG TERM STATISTICS 6 3 1 Calculation of long term statistics This chapter describes the theory related to the calculation of long term statistics which 1s applied in the VERES Postprocessor The short term statistics discussed in the previous chapter are calculated for a certain sea state where the significant wave height and mean period are assumed constant A sea state has a limited duration often set to three hours and a ship will encounter many sea states on a voyage during a year in service or during its lifetime Long term statistics provide predictions about the ship responses in such scenarios When calculating long term statstics the period of time considered is longer than the duration of one sea state i e the significant wave height and mean period will vary The probability of occurrence of the sea states is therefore needed The joint probability of significant wave heights H and characteristic periods T 1s commonly presented as a wave sc
32. areas occupied by passengers or crew most remote from the pitch and roll centre of the vessel Designers wishing to minimize the motion sickness should avoid or reduce vibration in the range of 0 1 to 0 315 Hz periods of 3 10 sec In addition to the ISO 2631 standard Motion Sickness Incidence MSI McCauley et al 21 can also be applied as a criterion for passenger comfort MSI operability criteria are specified by the percentage of crew being seasick for a given exposure time see Section 6 2 5 for details P 2004 12 21 SHIPX Vessel Responses Users Manual Postprocessor Reference 6 28 MARINTEK Table 6 4 Comfort criteria for passengers and crew 11 CRITERIA DESCRIPTION RMS VERTICAL ACC Exposure hour hour 2 hours 8 hours Simple light work possible Light manual work possible Heavy manual work Work of more demanding type Passenger on a ferry Passenger on a cruise liner ROLL Light manual work Demanding work Passengers on a ferry Passenger on a cruise liner PITCH Navy crew Light manual work Demanding work HORIZONTAL ACC Passenger on a ferry Navy crew Standing passenger 0 025 g 0 050 g 0 07 g max 0 08 g max Seated person 0 15 g max 0 25 g max 0 15 g max 0 45 g max COMMENT 1090 motion sickness incidence ratio MSI vomiting among infrequent travelers of the general public One third octave band frequency analysis 1s recommended Most of the
33. be included in text reports a Edit Lightship Weight gives access to the lightship weight input a Edit Structural Characteristics gives access to the Structural Characteristics input dialog only relevant if you have access to the Strength Assessment Plug In a Explore opens the corresponding directory in the SHIPX database file structure where different files for the current hull and associated runs are stored You can also store other documents related to the ship in the Related documents folder where they will be available by clicking the Re ated documents node the Database Browser u From the context menu of the hull it is possible to generate text reports on main dimensions and stability calculations for the design draught see the open sub menu in Figure 3 5 a Ships can be duplicated by selecting Duplicate and deleted by selecting Delete 4 Edit Hull Hull Transformation E53 Edit Principal Characteristics Edit Ship Model Characteristics fy Edit Lightship weight ILI Edit Structural Characteristics ig Mew Loading Condition Explore Reports d Principal Hull Data Report zx Duplicate Principal Hull Data Report including model scale data Delete Ship Hydrastatics Report ship Hwdrostatics Report including model scale data Generate amp View GLview File it Refresh Figure 3 5 Context menu for a ship in the Database Browser P 2004 12 21 SHIPX Vessel Responses User s Manu
34. calculate the exciting forces and hydrodynamic forces To ensure consistent data the hydrodynamic coefficients applied in the motion calculations are evaluated in the same manner as in the global load calculations 5 6 3 Input Description The following section will briefly describe how to specify the input required for global load calculations The main choices concerning calculation method and mass input type 1s chosen in the Calculation Options dialog In addition the specification of transverse and longitudinal cuts 1s available from this dialog The definition of cutsas well as the mass input 1s described below P 2004 12 21 SHIPX Vessel Responses Users Manual 5 17 MARI NTEK Postprocessor Reference Calculation Options Calculation options Global loads options e s Ordinary strip theory t Continuous mass distribution t Direct pressure integration Discrete weights ERES W Calculate global loads Torsional moments lgnore mass balance check addedie tance Humber of transverse cuts E Specify Lig not calculate Output Motion coordinate system if Generate STRIP STR file Generate hydrodynamic coefficients file ref f Z coordinates fram waterline e Z zpordinate from COG Cancel Help Figure 5 6 The Calculation Options Dialog Defining cuts The transverse and longitudinal cuts are defined in the Calculation Options dialog Figure 5 6 The o
35. can be calculated as pas a 6 60 where n 15 the permissible number of slams per hour 15 the zero crossing period of the relative motions in seconds Green water on deck The limiting significant wave height due to the probability of green water on deck 15 obtained by F IH m 0 Vv 2 In f dw 6 61 where Paw 15 the permissible probability of deck wetness specified by the user If the user has specified the permissible number of events per hour rather than the probabilitv the probabilitv can be calculated bv 6 60 F is the user specified freeboard at the considered longitudal location 15 RMS value of relative vertical motion per meter significant wave height If a relative motion calibration file xmc is specified for the motion point in question the relative motion transfer functions will be calibrated before calculating the RMS value g See Section 6 1 4 page 6 4 for details If a two parameter JONSWAP spectrum is applied 1 the statistical respose 15 not linear with respect to H an iteration is performed to ensure that 1s calculated with correct H and y value Otherwise a unit wave height 1s applied P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 32 Air exposure The limiting significant wave height due to the probability of air exposure is obtained by d Him gn gr v 21m Fair 6 62 where Par 1s the
36. g 1s the acceleration of gravity Lpp 15 the vessel length between the perpendiculars and is wave amplitude a The real and imaginary parts of the complex transfer functions are related to the wave elevation at the center of gravity 1 e the phase angle gives the phase lead relative to a wave crest at the longitudinal center of gravity Changes in this file format No changes have been made since version 3 00 Please note that this file format 15 slightly changed in VERES Version 3 00 and future versions To be consistent with the change in the rel files the variables XMTN and ZMTN are included for each velocity P 2004 12 21 SHIPX Vessel Responses Users Manual 77 MARI NTEK Appendix 7 1 3 Generalized transfer functions file re5 This section describes the file that contains output of generalized transfer functions from the VERES program In addition to motions it can also be applied for other quantities that can be expressed by transfer functions The format of version 1 0 of this file 1s OPEN ACCESS SEQUENTIAL FORM FORMATTED PROGVER FILEVER FILETYP 5 CARDID 1 CARDID 2 CARDID 3 CARDID 4 CARDID 5 RHOSW GRAV LSCALE LPP BREADTH DRAUGHT XCG ZCG NOVEL NOHEAD NOFREQ NRESPS do ires 1 NRESPS RESPID ires ISYM ires RESUNIT ires RESTXT ires enddo do ivel 1 NOVEL TREHYD ICO ICO 1 3 RREHYD ICO ICO 1 3 do ihead 1 NOHEAD do ifreg 1 NOFREQ VEL ivel HE
37. induced loads can be calculated A right handed sign convention 1s used for the shear forces as well as the bending and torsional moments Note that the sign convention applies to the forces and moments acting on the portion of the ship forward of the transverse cuts and on the portion of the ship to the starboard of the longitudinal cuts As for the motions the global loads can be expressed as Vit K cosl k z 0 5 14 where Vka is the force amplitude for mode k and is the corresponding phase angle V V represents the forces in the and z direction while V V represents the moment components about the x y and z axis respectively The dynamic forces and moments can be calculated as the difference between the inertia force and the sum of the external forces acting on the portion forward of the cut in question or to starboard in case of longitudinal cuts This can be expressed formally as Br B kolan 5 15 where is the inertia force moment and the external force moment is divided into restoring forces Ri exciting forces and hydrodynamic forces due to the vessel motions Dx When the traditional strip theory developed by Salvesen Tuck amp Faltinsen 27 1s applied the exciting forces and hydrodynamic forces are calculated using the strip theory approach while the direct pressure integration divides the hull into panels and applies the pressure components at each panel to
38. likely to be present such that the waves are travelling 1n several different directions simultaneously The primary wave direction can easily be recognised and is usually more or less aligned with the wind direction Changes in wind direction topological influence due to e g the coastline and bottom and the prescence of wave systems coming from elsewhere will all lead to a certain amount of wave spreading The interaction between different long crested wave systems results in alternate enchancement and cancellation of wave crests and troughs commonly referred to as short crested seas to describe a wave system with a spread of wave directions A common way to describe a short crested sea state 1s to apply a cosine power spreading function so that the directional spectrum can be written as Ot wg V D cos 2 0 i S wo 6 39 t LV max where vis the wave direction u is the primary wave direction and Vnax 1s the wave spreading angle To simplify the expression we define the relative wave direction v as U v p 6 40 AL mar giving the equation for the directional spectrum as Selwo V D cos v Se wo 6 41 The constant D 1s a normalization factor so that the total integrated wave energy over all the wave headings from Ving lt lt Vmax 18 the same for all values of m and Vnax l 3 5 7 1n Ue D az 1 6 m l uma z if n IS odd 6
39. moment about local z axis Horizontal bending moment The forces and moments are obtained by approaching the cut from the starboard hull side The wave induced global forces and moments calculated by VERES are explained in Figure 5 4 and Figure 5 5 Figure 5 4 displays the forces and moments at a transverse cut whereas Figure 5 5 represents a longitudinal cut The selection of longitudinal cuts 1s an option only if you are studying a multihull refer Table 5 1 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 5 13 Figure 5 4 Transverse cut Fi and F represents the longitudinal tension force horizontal shear force and vertical shear force respectively M M and are the torsional moment the vertical bending moment and the horizontal bending moment The forces and moments are obtained by approaching the cut from the bow Figure 5 5 Longitudinal cut Fi F2 and represents the horizontal shear force the transverse tension force and the vertical shear force respectively and M are the vertical bending moment the torsional moment and the horizontal bending moment The forces and moments are obtained by approaching the cut from the starboard hull side P 2004 12 21 SHIPX Vessel Responses Users Manual 5 16 MARI NTE Postprocessor Reference 5 6 2 Outline of theory After the hydrodynamic problem and the motions has been solved Section 5 4 the wave
40. of the responses are simply half the double amplitude in linear theory P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 17 0 5772 1 3600 V2InN I B Ua 205 v21n N 6 47 where T is the zero upcrossing period of the response which for forward speed will differ significantly from the zero upcrossing period of the waves Tz The zero upcrossing period of the response may be calculated from 6 48 j 7 me Average of the I nth highest response amplitudes double amplitude can be found by e __ na Tj 2 I il erf vlnn v21 I n e 5 CTI nn TA m 6 49 The calculated response values will be linear with respect to the significant wave height H if a fixed value of the peakedness parameter 15 used Thus the corresponding value for a different value of the significant wave height can be found by multiplying the response value by the actual significant wave height 6 2 4 Motion Induced Interruptions MII section 6 1 5 describes the calculation of the lateral force estimator LFE which is the lateral acceleration percieved in the plane of the ship s deck by an object or person It is this acceleration which makes objects topple or slide across the deck and people lose their balance Graham 12 presents the concept of using the number of Motion Induced Interruptions MIIs per minute as an operability cr
41. pointing upwards from the base line BL and the y axis 1s positive to starboard Furthermore the station numbering in the output files and error messages is converted to correspond to the numbering in SHIPX 1 e numbered from aft increasing when moving forwards P 2004 12 21 MARINTEK SHIPX Vessel Responses User s Manual Introduction P 2004 12 21 2 8 SHIPX Vessel Responses User s Manual 31 MARINTEK s 3 SHIPX SHIPX is MARINTEK s common platform for ship design analyses The system is a unique workbench environment that facilitates simple and efficient integration of different applications and components The system is based on a state of the art computer architecture which gives a large degree of flexibility with respect to scaling implementation languages and technologv Finally it is built on a common representation model for common vessel information which facilitates efficient exchange of information between different ship design applications The main aim of SHIPX 1s that input should be given once during the design process In addition a common workbench will facilitate re use and generalisation of user interface components increasing familiarity and reducing the user threshold for all tasks involved This chapter gives a simple introduction to the SHIPX system explains the basic concepts and describes the practical use of the system Contents 3 2 6 Common Settings 3 11 3 SHIPX
42. the VERES Postprocessor is as follows 1 The average long term response period 7 is calculated see Section 6 3 for details 2 The total number of response cycles N during the specified design life is calculated according to 6 54 3 The maximum stress range 15 calculated based on the probability of one occurrence during the design life period 1 Mio 4 The range from zero to the maximum stress range is divided into 30 equally spaced stress range blocks 5 The long term probability of exceeding each of the stress block limits is calculated 6 Based on the 30 calculated values 600 new stress range blocks are generated by interpolation on the stress range versus the logarithm of the probability of exceedance 1020 which should form a nearly straight line This is done to ensure that the final sum will converge 7 Based on this the number of stress cycles in each of the stress blocks n 1s calculated The number of cycles to failure in stress block N 1s calculated by means of the specified S N curve applying the maximum stress range in each block as input 9 The fatigue damage D is calculated by 6 69 and multiplied with the fraction of design life in the actual loading condition P 2004 12 21 SHIPX Vessel Responses Users Manual 6 42 MARI NTE Postprocessor Reference 6 6 SLAMMING This chapter describes the calculations related to slamming in VERES Some of the material here can be found outher place
43. the different steps in the calculation process and can serve as training for a new user of the program The hull used for this exercise is a standard container ship called S 175 Figure 4 1 and can be found in the c Program Files SHIPX PlugIns VERES Examples folder together with the other files needed for this example This hull is used throughout the manual as reference calculation and the main characteristics are given in Table 4 1 Table 4 1 Main characteristics for the S 175 Length between perpendiculars Lpp m 175 0 Breadth max moulded 5 m 25 4 Draugh m 9 5 Displacement tonnes 24000 Block coefficient 0 572 NIAE NE NES SEE ZJ ZAMEK STII LU n NULLE LUAM TN REIS DADEN _ oA a L ES c lm Figure 4 1 The S 175 hull form Section 4 2 gives a brief introduction to the Vessel Response calculation part of the Plug In defining input data for the S 175 vessel and explains how to import the hull lines into SHIPX define the loading condition and run the program A short description of the Postprocessor 1s given in Section 4 3 Formerly known as the VERES Main Program P 2004 12 21 SHIPX Vessel Responses Users Manual 43 MARI NTEK Hands on Introduction to VERES 4 2 CALCULATING VESSEL RESPONSES IN WAVES The Vessel Response calculation Run provides an easy way for the user to give and check the input data needed to perform vessel response calculations as well as performing t
44. the motion transfer functions with the specified wave spectra to obtain the response spectra short term statistics 3 The response spectra are combined with the specified seakeeping criteria to obtain operability limiting boundaries 4 The operability limiting boundaries combined with the specified wave scatter diagram are summed up over the sea states to obtain the percentage operability Specified by the user Vessel data Transfer function Response Seakeeping spectrum criteria Roll 4deg Vert acc 0 159 Slamming 3 Green water 7 Op lim Wave scatter boundaries diagram un pi e T t PUTET Calculated Figure 2 1 The prinsiple calculations performed by VERES to obtain the percentage operability P 2004 12 21 SHIPX Vessel Responses User s Manual 24 MARI NTE Introduction 2 2 1 Formulations VERES can be applied on monohulls and catamarans at low as well as high speed At low and moderate speeds Froude numbers up to 0 25 0 30 you can solve the problem by the traditional strip theory developed by Salvesen Tuck amp Faltinsen 27 At higher speeds Froude numbers larger than approximately 0 4 the high speed formulation developed by Faltinsen amp Zhao 10 can be applied In the Froude number range of 0 3 0 4 a comparison between the two methods should be carried out A formulation for high speed catamarans 15 also included This formulation accounts for hull interacti
45. the phase angles have no meaning are left blank Degree of freedom Suge 4 2395 JJ J 4 69i b O 090 Sway 8 Have 00 _ 0 J 2 0 Roll ich 6 1 3 Relative motions between the ship and the wave Slamming and deck wetness are of considerable importance in assessing the seakeeping performance of a ship These qualities are largely determined by the magnitude of the relative motions and velocities between the hull and the adjacent sea surface The relative vertical motions between the ship and the waves can be calculated in the postprocessor assuming that the waves are undisturbed by the presence of the ship The relative motions as well as velocities and accelerations can be presented as transfer functions with RAO s and phase angles The relative vertical motions at a position x y z on the vessel are calculated as NSZ Z TORU ZJ CUu 6 3 where 773 18 the complex amplitude of the relative vertical motions 731s the complex amplitude of the local vertical motions amp y is the undisturbed wave elevation at the given position which can be expressed as SE EJ A ZE ik x cos 84 ysin 3 6 4 where k is the infinite depth wave number f is the wave heading and the calculations are performed with a unit wave amplitude For correct calculation of slamming statistics the relative vertical velocities are calculated as suggested by Faltinsen 9 Vgp
46. transverse cuts Index showing if the force in direction 1 is calculated for the longitudinal cuts Index showing if the moment about the 1 axis is calculated for the longitudinal cuts Position of longitudinal moment axis y z Position of transverse moment axis X Z X Positions of transverse cuts y Positions of longitudinal cuts Number of vessel velocities Number of wave headings Number of wave frequencies Vessel velocity Sinkage at a given velocity Trim at a given velocity X pos of the motion coordinate system rel L 2 Z pos of the motion coordinate system rel to BL Wave heading Wave frequency Longitudinal distribution of global forces on transverse cuts P 2004 12 21 Type e 4 mlllz M M ia ia mis ia ia ia Mr Mrs rs Unit x go NZ 3 3858888588585 rad s 1 5 SHIPX Vessel Responses Users Manual MARINTEK Appendix 7 6 Variable Description Type Unit GLFCET Transverse distribution of global forces on C longitudinal cuts GLMOML Longitudinal distribution of global moments at C transverse cuts GLMOMT Transverse distribution of global moments at C longitudinal cuts The following definitions apply a The complex transfer functions for the forces are defined as GLFC H t d za A 1 pg La Further the moments are defined as M GLMOM i A 2 pg Lr Ga where i denotes the direction p 1s the density of sea water
47. where the vessel will operate or because the vessel will try to keep a certain heading relative to the waves e g support vessels with dynamic positioning DP equipment Thus three different approaches are implemented in the VERES Postprocessor in order to meet the needs of different users These are a Calculations on each heading separately a Input of the probability of each heading a All headings have equal probability of occurrence The calculation method is specified in the Long Term Statistics dialog The first and last method needs no further input from the user If the user chooses to input the probability of each heading separately the fraction of time of each heading angle must be specified The resulting long term responses will then be a weighed sum of each heading response multiplied with its probability of Occurrence One thing is worth mentioning It is common practice to perform calculations on wave headings 0 to 180 rather than 0 to 360 in many cases since e g the motion transferfunctions on locations on the centerplane will be symmetric for waves approaching from either side of the centerplane To perform a long term analysis of the response with equal weighting of all wave headings from 0 to 360 one should then half the probability of occurence for wave headings 0 and 180 as the other wave headings should count twice one for waves approaching from starboard and one for the same wave approaching from port In th
48. will appear for the objects in the database which regulate locking the data for editing by a single user checking in out data You can read more about the SHIPX database in Section 3 20 Database configuration is treated specifically in Section 3 2 7 3 1 4 Standard SHIPX dialog buttons At the bottom of all standard SHIPX dialogs you will find a row of buttons with standard functionality that you should get familiar with Depending on the width of the dialog the button row will either be standard including descriptive text or compressed icons only Figure 3 4 shows examples of this button row 4 Cancel Y Apply Reset 4 w i Standard Compressed 4 OK Eg Check In dig Check In amp Close 4 5 i EG Mig Standard multi user Compressed multi user Figure 3 4 SHIPX dialog buttons P 2004 12 21 SHIPX Vessel Responses User s Manual 2 6 MARINTEK s The functionality for each of the buttons 1s as follows 4 OK Applies the values and closes the dialog window i Cancel Discards all new values and closes the dialog window Apply Applies the values to the database without closing the dialog window i Reset Resets the values in the dialog window reads them again from the database Applies the values saves them and makes them available to other users without closing the dialog window same as above but closes the dialog window 1 e same as OK but including the Ch
49. will be continuously distributed along the centerline of the vessel and that the local VCG may vary longitudinally 2 By selecting Discrete masses in the Calculation Options dialog Figure 5 6 The total mass will now be represented by discrete masses of varying size and varying longitudinal transverse and vertical position Notice that only the mass points on the starboard side are needed since VERES assumes symmetric mass distribution about the centerline By clicking the Mass Distribution button in the Edit input part of the VERES main dialog window you will access the Mass Distribution Data dialog This dialog will be approximately the same whether you choose continuous or discrete mass distribution An example of the dialog is given in Figure 5 8 where a discrete distribution was selected Mass Distribution Data Edit mass point data Longitudinal position x Transverse position y Vertical position 2 Mass Mass Point Distribution Data Mass kal Longitudinal position A Total mass B Calculated displacement BST OOOO 5379 4033 EE Transverse position 24835 375 tonne 24589 47 tonnes Displ mass points A 0 990 LCG 95 071 m LCE 04 948 p LCB LCG 0 123 m YEG 9 550 Figure 5 8 The Mass Distribution Data Dialog m rel AP n Modity m above BL kg Remove Vertical Transform position i m VERES Report Plot Number ot values Import Da
50. z y z 73 2 9 2 w z y Ung 6 5 where U is the ship speed and o is the vertical component of the undisturbed wave velocity in the free surface at the point considered The relative vertical accelerations are calculated by taking the time derivative of the relative vertical velocity In practice the prescence of the hull causes a considerable distortion of the waves close to the ship and the above equations are only likely to be reliable at the forward perpendicular Further aft the error in the relative motions may be considerable For bottom slamming in the bow region the above assumptions are relevant since the bow 1s assumed to go out of the water and re enter with P 2004 12 21 SHIPX Vessel Responses Users Manual 64 MARI NTE Postprocessor Reference a certain velocity The waves will then be undisturbed by the prescence of the ship at the time of impact See also the next section regarding calibration of relative vertical motions 6 1 4 Calibration of relative vertical motions The VERES Postprocessor includes an option to include a calibration file rmc to calibrate the relative motion transfer functions at a given motion point on the ship In this case the transfer functions are multiplied with a calibration factor which can be dependent on speed heading and frequency This option can be applied to calibrate relative motions with model test results and thus enable the user to perform calculations with more
51. 12 21 SHIPX Vessel Responses Users Manual MARINTEK Appendix 7 9 7 1 4 Dynamic pressure distribution re6 This section describes the file that contains output of the total dynamic pressure distribution from the VERES program The format of version 1 0 of this file 1s OPEN ACCESS SEQUENTIAL FORM FORMATTED PROGVER FILEVER FILETYP 26 CARDID 1 CARDID 2 CARDID 23 CARDID 4 CARDID 5 RHOSW GRAV LSCALE LPP BREADTH DRAUGHT XCG ZCG NOVEL NOHEAD NOFREQ do ivelz1 NOVEL TREHYD ICO ICOz1 3 RREHYD ICO ICOz1 23 NHULL ivel do ihullz1 NHULL ivel NHPANS ivel ihull do ipan 1 NHPANS ivel ihull do ipnt 1 4 X ipnt Y ipnt Zz ipnt enddo enddo enddo NFOILS ivel do ifoil 1 NFOILS ivel XCEN ivel ifoil YCEN ZCEN XCON YCON ZCON enddo do ihead 1 NOHEAD do ifreq 1 NOFREQ VEL ivel HEAD ihead FREQ ifreq do ihullz1 NHULL ivel do ipan 1 NHPANS ivel ihull Re CPRESS ivel ihead ifreq ihull ipan Im CPRESS Re FORCEX Im Re FORCEY Im Re FORCEZ Im enddo enddo do ifoil 1 NFOILS ivel Re FCENX ivel ihead ifreq ifoil Im Re X Im Re Z Im enddo enddo enddo P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Appendix Here Variable PROGVER FILEVER FILETYP CARDID 1 5 RHOSW GRAV LSCALE LPP BREADTH DRAUGHT XCG ACG NOVEL NOHEAD NOFREQ TREHYD RREHYD NHULL NHPANS NFOILS XCEN ZCEN XCON
52. 1s obtained if each discrete mass 1s multiplied with a factor 0 990 and moved longitudinally 0 123 m towards the stern These values which are required to obtain consistency between mass input and load condition are default and they appear in the Transform Mass Values dialog Figure 5 9 Transform Mass Values Specify transformation factors Mass multiplication factor Displacement of x values Displacement of L values O00 Scale factor for values O00 Cancel Scale factor for values O00 Scale Factor For L values DOO Help Please nate the following The coordinates are first multiplied with the scale Factor and then transformed with the displacement value Figure 5 9 The Transform Mass Values Dialog 1 The load condition is specified by the draught sinkage and trim of the vessel P 2004 12 21 SHIPX Vessel Responses Users Manual 521 MARI NTE K Postprocessor Reference The mass distribution can be changed in several ways The possible alterations are l By multiplying the masses with a factor the total mass can be increased decreased in order to match the displacement calculated by VERES The masses can be moved a distance in the x direction to obtain a new LCG that will match the calculated LCB The vertical center of gravity VCG can be changed by moving the masses a distance in the z direction It might be desirable to change the radii of gyration In pitch Rss the radius will be increased
53. 2 21 SHIPX Vessel Responses User s Manual MARINTEK six 3 17 3 4 2 Hull transformation Global transformations of the hull lines can be performed by using the Hull Transformation tool The Hull Transformation tool can be started by choosing Hull Transformation from the menu found by right clicking the hull geometry in the Database Browser or selecting the ToolslHull Transformation menu Hull transformation includes the following options Scaling by changing the main characteristics Shape change by changing the prismatic coefficient and or LCB Elongation Filter stations to reduce the noumer of stations or points per station D D D D UD Filter contours to reduce the number of points on the contour lines Hull Transformation Ship Demo EM Hull Transformation Ship Demo 1 E Hull Transformation Ship Demo Main Characteristics Cp LCB Elongation Filter Stations Filter Contours Main Characteristics Cp amp LCB Elongation Filter Stations Filter Contours Main Characteristics Cp amp LCB Elongation New length between perpendiculars Lpp 24 00 m New Cp l ad Position of elongation m New breadth at design waterline Bwl 9 000 m New LCB rel Lpp 2 0198 Extent of elongation 0 00 m New design draught T 4000 m New rake of keel 036m New rake of keel 0 96 m New rake of keel 0 36 m Fixed aftship Fixed foreship
54. 2 31 10 2003 10 00 20 73 0 KB ostre ensis Ship Utilities DLL Library 27 02 2003 15 21 36 30 09 2003 11 33 54 118 0KB Graphics ZIP archive New File 02 10 2003 11 21 01 118 0KB Graphics ZIP archive extractor Java class file 11 01 2002 15 15 13 15 05 2003 13 17 21 3 0KB License Key Update Utility 1 00 0021 1 00 0027 73 0 KB Update log for Ships Workbench New File 16 01 2004 03 17 36 5 0 KB Initialization file for Ships Workbench update log New File 22 10 2003 13 22 35 0 0 KB UltraSuite Data Masking Control 19 12 2001 16 22 16 14 10 2002 16 39 46 40 0 KB UltraSuite Print Utility New File 13 05 2002 12 44 24 106 0 KB UltraSuite Toolbar Control New File 05 11 2002 16 17 18 487 0 KB UltraSuite Grid Control New File 11 12 2002 17 18 58 1138 0 KB ShipShape DLL Library 14 01 2004 03 38 26 16 01 2004 03 15 57 12 332 0 KB Ship Uninstall Cleaner New File 1 00 0023 28 0 KB Remove amp ddComp New File 15 10 2002 12 55 46 0 0 KB Ship Java Library 25 02 2003 10 08 03 06 02 2004 12 15 18 1532 0 KB Ships Java COM Library 26 02 2003 10 08 03 03 10 2003 09 04 46 1 139 0 KB Ships Java Type Library New File 03 10 2003 09 04 44 2 271 0 KB Jlntegra JAR files and dependencies New File 02 03 2003 09 39 29 453 0 KB JIntegra Configuration Check File New File 21 06 2002 10 10 38 49 0 KB v Description Update Information Time to download at 56 Kbps 2 hrs 34 min 13 sec Total download size Figure 3 10 Automatic update utility that shows up if new or updated c
55. 5000 m Fred of AP DK 0000 m off center starboard Z 12000 m above Base Line p Slamming properties k factor ion Threshold velocity Werk 0000 m sec Threshold pressure Perit o000 kPa Relative motion calibration file Modify Copy from Point properties File point position Y pasitien position epolt 175 00 0 00 12 00 Yerit Slamming Report Relative Motion Report Number of points Figure 4 22 The Specify Points Positions dialog 7 To specify a motion point on the hull click the Define points positions button to get to the Specify Points Positions dialog Here you can add a new motion point by giving it a name and the position on the hull in x and z coordinates In this example let us call the motion point FP Fore Prependicular After typing FP in the Description text box click the Add button Further select points for one file in the View box in the upper part of the dialog Boxes where you may specify the coordinates should now appear in the Edit motion point box Specify the longitudinal position to be 175 0 m fwd of AP and the vertical position to 12 0 m above the base line Finally click the Modify button to add the coordinates to the Motion point description list The Specify Points Positions dialog should now look like Figure 4 22 Click OK to return
56. AD ihead FREQ ifreq do l 1 NRESPS RESPID 1 RETRANS 1 ifreq ihead ivel IMTRANS 1 ifreq ihead ivel enddo enddo enddo enddo Here Variable Description Type Unit gt PROGVER Program version R FILEVER File format version R FILETYP File type 5 for re5 I CARDID 1 5 Vessel identifying text Char RHOSW Density of water R kg m GRAV Acceleration of gravity R m s LSCALE Length parameter used for non dimensionalization R m LPP Length between the perpendiculars R BREADTH Vessel breadth R DRAUGHT Vessel draught R XCG Longitudinal center of gravity rel L 2 R ZCG Vertical center of gravity rel BL R NOVEL Number of vessel velocities I NOHEAD Number of wave headings I NOFREQ Number of wave frequencies I NRESPS Number of responses I RESPID ID number for each response counting from 1 to NRESPS I ToxXM Symmetry property for each response 1 0 1 for I P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Appendix 7 8 Variable Description Type Unit antisymmetric no symmetry or symmetric properties regarding symmetric headings e g 30 and 330 RESUNIT Unit for each response must be a continuous text string Char RESTXT Description text for each response Char TREHYD Components of the vector pointing from origin R of the hydro coordinate system to the intersection point between the planes formed by BL CL and AP RREHYD Rotations of the hydro coordinate system that are R ra
57. ION OF COORDINATE SYSTEMS WAVE HEADING AND MOTIONS The input in the graphical user interface of VERES is related to the same definitions as the rest of ShipX 1 e a left handed coordinate system x y z with the x axis positive forwards with its origin at the aft perpendicular AP the y axis positive to starboard origin at centerline and z axis pointing upwards from the baseline Internally VERES uses two right handed Cartesian coordinate systems one global coordinate system x y z in which the computations are performed and a local coordinate system x Vi zi used to describe the cross sectional geometry of the vessel in the hull geometry file refer to Section 5 3 1 for details Figure 5 1 Definition of global coordinate system and wave heading angle The x y plane of the global coordinate system coincides with the still water plane while the x z plane coincides with the center plane of the vessel The x axis 1s directed towards the stern and the z axis 1s pointed vertically upwards through the center of gravity of the vessel The wave heading angle is defined as the angle between the positive x axis and the wave propagation direction Hence a wave heading angle of 0 degrees corresponds to head seas 90 degrees corresponds to beam seas and 180 degrees corresponds to following seas A sketch defining the coordinates and the wave heading angle 2 15 shown in Figure 5 1 The translatory displacements 1n the x y and z direction
58. MARINTEK MARINTEK REPORT Norwegian Marine Technology Research Institute Postal address P O Box 4125 Valentinlyst SHIPX Vessel Responses VERES O a A Ship Motions and Global Loads Location Marine Technology Centre Users Manual Otto Nielsens veg 10 Phone 47 7359 5500 Fax 47 7359 5776 http www marintek sintef no Enterprise No NO 937 357 370 MVA Dariusz Fathi Multiclient FILE CODE CLASSIFICATION CLIENTS REF CLASS THIS PAGE ISBN PROJECT NO NO OF PAGES APPENDICES mundi REFERENCE NO PROJECT MANAGER NAME SIGN VERIFIED BY NAME SIGN shipx vessel responses 00 doc P Dariusz Fathi Jan Roger Hoff REPORT NO DATE APPROVED BY NAME POSITION SIGN 2004 12 21 Terje Nedrelid ABSTRACT This report describes the SHIPX Vessel Responses Plug In VERES which can be used to calculate motion responses and global loads applying various strip theory formulations ranging from zero to high forward speed The available options will depend of the type of license you have KEYWORDS ENGLISH NORWEGIAN Hydrodynamics Hydrodynamikk SELECTED BY AUTHOR MARINTEK SHIPX Vessel Responses Users Manual P 2004 12 21 SHIPX Vessel Responses VERES Ship Motions and Global loads Preface The study of wave induced vessel responses is essential in the design of new ships To optimize the operabilitv of the vessel in a seaway it 1s important to minimize the motions of the ship If the loads are decr
59. Process List sy Hull element generation S Vessel Responses in Waves Turn mouse movement dependant scrolling on off Figure 3 1 The SuiPX Workbench P 2004 12 21 TO HW POP 2004 02 10 12 23 SHIPX Vessel Responses User s Manual MARINTEK six 3 3 3 1 2 Plug Ins Most functionality in SHIPX is implemented in so called P ug ns A Plug In connects with the workbench and extends the functionality of the workbench with new buttons menu choices user interface components etc This concept makes it simple to extend SHIPX with new functionality and to customise it for special users Only the Plug Ins that are currently loaded into SHIPX and that are included in the license will be available for the user After a standard installation all licensed Plug Ins will be added automatically and there will be no need for the user to register any Plug Ins manually For advanced users one can control which Plug Ins that are loaded through the Plug In Manager see Figure 3 2 The Plug In Manager can be accessed through the Plug Ins menu An overview of available and planned Plug Ins are listed in Table 3 1 and Table 3 2 on page 3 18 Plug In Manager Available Plug Ins Load Behaviour Basic Propulzor Input startup f Loaded Basic Ship Input Startup I Loaded Register Import amp Export Filters startup i Loaded ShipShape Import Filter Startup f Loaded Unregister Graphics Startup f Loaded Hull Manipulation S
60. TRANS Imaginary part of complex motion RAO R The following definitions applv a The motion transfer functions RAOs are defined as the motion amplitude divided by wave amplitude for all degrees of freedom The rotational motions are given in radians hence the motion RAOs will be in rad m a The motion transfer functions are given in the global coordinate system i e in the waterline with the z axis pointing through center of gravity a The real and imaginary parts of the complex motion transfer functions are related to the wave elevation at the center of gravity 1 e the phase angle gives the phase lead relative to a wave crest at the longitudinal center of gravity Changes in this file format No changes have been made since version 3 00 Please note that this file format is slightly changed in versions after VERES Version 2 10 For versions before version 2 10 VCG 15 given relative to the waterline WL the motion coordinate system while for versions after 2 10 VCG is given relative to the base line BL In addition the position of the motion coordinate system 1s given separately by the values XMTN and ZMTN for each velocity This gives two advantages 1 The position of the center of gravity can be specified relative to the hull geometry 1ndependent of the waterline 2 The motion coordinate system can be specified separately for each velocity and does not need to have any connections to the waterline and LCG The o
61. X Vessel Responses Plug In is a SHIPX implementation of the VEssel RESponse program VERES which is intended to be a tool that can be used in early design in defining and evaluating model tests and in obtaining supplimentary results The program calculates Motion transfer functions in six degrees of freedom Relative motion transfer functions Motion transfer functions at specified points Global wave induced loads forces and moments Short term statistics of the above mentioned Long term statistics of the above mentioned Postprocessing of slamming pressures Operability operability limiting boundaries operability diagrams for a given sea state and percentage operability DOCO DODDO Here motions include displacements velocities and accelerations Please note that the options you have available will depend on what kind of license you have Some modules may require an additional license All computer programs for calculation of ship motions are based on assumptions and simplifications with respect to theory and hull form representation In order to use the program in practical design it is important to be aware of the limitations of the program and to which extent the results are valid In theoretical terms the theory applied in the VERES program is said to be based on linear potential strip theory The relevance of these restrictions is that the theory is developed for moderate wave heights inducing moderate motions on a ship wi
62. YCON ZCON VEL HEAD FREQ CPRESS FORCEX FORCEY FORCEZ FCENX FCENY FCENZ Description Program version File format version File type 76 for re6 Vessel identifying text Density of water Acceleration of gravity Length parameter used for non dimensionalization Length between the perpendiculars Vessel breadth Vessel draught Longitudinal center of gravity rel L 2 Vertical center of gravity rel BL Number of vessel velocities Number of wave headings Number of wave frequencies Components of the vector pointing from origin of the hydro coordinate system to the intersection point between the planes formed by BL CL and AP Rotations of the hydro coordinate system that are needed in order to make the x axis point towards the bow Number of hulls on the vessel Number of panels on each hull Number of control surfaces foils etc Coordinates for the corner points of the panel given in a counterclockwise direction right hand rule with normal vector outwards The coordinates are given relative to the waterline for the given draught sinkage and trim hydro coordinate system Coordinates of the center of each foil Coordinates of the point where each foils is connected to the hull Vessel velocity Wave heading Wave frequency Hydrodynamic pressure acting on each panel Components of the viscous force acting on each panel Components of the force acting on each foil at XCEN Y CEN ZCEN Th
63. able At high speeds this 1s a reasonable assumption since the waves will travel downstream and if the hulls are not too narrow interaction effects will be small At low and moderate speeds interaction effects may be important As mentioned VERES assumes the ship to be slender The motivation for this simplification is that the three dimensional problem may be reduced to a set of two dimensional problems along the hull This will save a lot of computational time The disadvantage of this method is that three dimensional effects are neglected For a tanker this simplification 1s acceptable except locally at the bow and stern For supply ships and fishing vessels three dimensional effects can be important To calculate hydrodynamic forces potential theory 15 used Potential theory assumes the fluid to be homogeneous non viscous and incompressible Thus viscous effects are not accounted for However in roll viscous effects should be accounted for since the potential damping is small VERES may take viscous effects into account by empirical formulas This is explained in Section gt 14 i 5 This assumption is correct when linear theory 15 correct P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 30 Even if some of the above simplifications may be speculative linear theory has been found to give very good results compared to three dimensional codes and to model tests 5 2 DEFINIT
64. al 39 MARINTEK s 3 2 3 Hull geometry The hull geometry 1s defined by stations 3D lines and contour lines SHIPX 15 not intended to be a drawing tool to draw the hull lines and the primary source for the hull definition should be through import of a file from a hull design program The hull lines can however be modified inside SHIPX see Section 3 4 for further details on hull geometry manipulation Even if it is possible to define hull moulded forms directly in SHIPX the most practical way is clearly to import the geometry from external programs The following import formats are currently supported VERES mgf NAPA macro available from MARINTEK AutoCad DXF must include only 3D geometry defined by polylines no flat drawing AutoShip dra AutoHydro gf gf1 ghf Shipshape lin a Shipshape project O O O D D O Please contact MARINTEK if other import formats are required If you have a file format that describes stations and contour lines writing an import filter 1s usually a quite simple task In addition to the menu choices in context menu hull lines can be visualised as a 3D drawing by clicking the 3D View button 0 VIEW on the command bar or from the Viewl3D View menu 3 2 4 Loading conditions Loading conditions are created by selecting New Loading Condition from the Ship context menu see Figure 3 5 Initially the ship 1s created with one loading condition The Design Loading Condition T
65. al loads calculated at the centerplane can be mirrored For other quantities as e g forces and moments in longitudinal cuts which are not on the centerplane calculations of all wave headings from 0 to 360 must be performed if one wishes to apply short crested seas for all wave headings PLEASE NOTE To get reasonable results when performing calculations with short crested seas it 1s important to make sure that enough wave headings are applied to give a good resolution over the wave spreading function Figure 6 3 As an example for a cosine squared distribution 1 e m 2 with a wave spreading angle of 4907 one should have a resolution of at most 30 between each wave heading and minimum 7 wave headings within the wave spreading interval P 2004 12 21 SHIPX Vessel Responses Users Manual 6 14 MARI NTE Postprocessor Reference 4675 0 0 1565 lu ia 0 1255 u D 1565 hm 0 0835 125 5 uil 0 0425 cu i 707 A CN fy A Primary wave direction 0 0115 foi Figure 6 4 Representation of directional spectrum at discrete heading intervals of 15 cosine squared distribution over X90 from Lloyd 20 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 15 6 2 3 Short term statistics of the response Short term statistics of the response is found by combining the response transfer function with a wave spectrum to obtain a response spectrum as a function of
66. at Transverse cut X 0 00 m 1 0 10 0 PROBABILITY 8 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 Single amplitudes MNm Je bull slope r Weibull slope h 0 b slope h 0 Jkn 30 b E OOkn 120 0 T OOkn 150 0 T QOkn 180 0 T 14 16 s Weibull slope h 0 8770 25 16 s Weibull slope h 0 8561 31 46 s Weibull slope 0 8472 m D D 3953535353999 OFF TT TT d U Uu u UU XA er re p kai ali enn Figure 6 8 Long term probability level of the vertical bending moment at midship The Weibull parameters are estimated based on the probability levels applied in the long term plots This means that to estimate Weibull parameter for a Fatigue Limit State FLS one should choose a long term plot with corresponding probability levels The following options are especially included for fatigue assessment in the VERES Postprocessor a Probability limits Fatigue Limit State FLS applying probability levels of exceedance of 10 10 and 107 a Probability limits Ultimate Limit State ULS applying probability levels of exceedance of 107 104 10 10 and 10 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 22 MARI NTE Postprocessor Reference Long term return period The VERES Postprocessor can plot long term results as a function of the long term return period in years rather than
67. ation 6 77 can then be rewritten as 0 1 M d P slamming exp T 6 50 207 For the threshold velocity Ochi 24 has suggested to use Va 0 0934 gL 6 81 where L is the ship length 6 6 3 Long term statistics Long term predictions of the slamming pressure can be calculated in the same manner as described in Chapter 6 3 by combining Equation 6 77 with the joint probability of each sea state in a scatter diagram To account for the acoustic pressure the probability that the acoustic pressure becomes larer than a given value pa at a specific point can be expressed as jA 1 P impact pressure gt p exp i 6 82 ay gt a i ptu t U r The long term slamming pressures are evaluated bv calculating the pressure using the k factor 6 77 and the acoustic pressure 6 82 for each probability level The lowest value 1s selected at each level P 2004 12 21 SHIPX Vessel Responses Users Manual 6 45 MARI NTE Postprocessor Reference 6 6 4 Summary of input The following table summarizes which input is required for the different slamming calculations in the VERES postprocessor Table 6 6 Required input for different slamming calculations Required input Required result k factor Threshold velocity Threshold pressure crit Pn Probability of slamming Ochi Threshold velocity Threshold pressure Pressure statistics Short term Long term
68. attention devoted to keeping balance Causes fatigue quickly Not tolerable for longer periods Limit in fishing vessels Long term tolerable for crew Limit for persons unused to ship motions Older people Lower threshold for vomiting to take place Personnel effectiveness Personnel effectiveness Short routes Safe footing Older people Safe footing Personnel safety Personnel effectiveness Personnel effectiveness 1 2 Hz frequency General public Non passenger and navy ships 99 will keep balance without need of holding Elderly person will keep balance when holding Average person will keep balance when holding Average person max load when holding Nervous person will start holding Persons will fall out of seats REFERENCE ISO 2631 3 1987 amp 1982 Conolly 1974 Mackay 1978 Payne 1976 Goto 1983 Lawther 1985 Comstock 1980 Hosoda 1985 Karppinen 1986 Karppinen 1986 Comstock 1980 Hosoda 1985 Hosoda 1985 ISO 2631 1 Hoberock 1977 Hoberock 1977 Hoberock 1977 Hoberock 1977 Ship safety and capasity Limiting values for the ship safety and capasity vary with the type of ship and recommending limiting values 1s difficult However slamming and shipping of green water are typical problems that impose large loads on most ships A permissible probability of occurrence of 3 for slamming and 7 for green water on deck is often recommended 23 Operational considerations Operational considera
69. atter diagram The scatter diagram is suitable for a certain ocean area and may be given for a year or for a certain season Figure 6 7 shows the annual wave scatter diagram for the North sea 14 The number of occurrences are given for combinations of H and the zero upcrossing period 7 The peak period T 1s also commonly used in wave scatter diagrams North sea area ll Annual Number of occurences 3 5 4 5 5 5 19 94 3 1 63 27 11 4 2 1 0 5 d i 2 5 4 5 5 5 6 5 9 5 Sum 23 l61 323 288 49 l6 1005 Hs and Tz values the middle values in each interval Figure 6 7 Annual wave scatter diagram for the North Sea P 2004 12 21 SHIPX Vessel Responses Users Manual 6 20 MARI NTE Postprocessor Reference Long term distribution Following the descriptions given by DNV for fatigue assessment 7 the long term probability distribution 1s obtained by a weighted summation over all sea states and headings all seastates all headings PI R E 2 lij FRi R Pij 50 where Pij is the probability of occurrence of a given sea state i combined with heading j r v Vv is the ratio between the crossing rates in a given sea state and the average crossing rate y gt is the average crossing rate V 35 4 l 18 the response zero crossing rate in sea state i and heading J Mrij is the kth order moment of the response see Equation 6 44 The short term
70. base P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK sex 3 7 3 2 THE SHIPX DATABASE To open an existing database locate the database by selecting the FilelOpen Database menu option or choose it from the recent database list at the bottom of the File menu To create a new database select FilelNew Database and browse to an empty catalog where the database should be created You will be prompted for a database name shown at the top level 1n the Database Browser and to select wether the database should be multi or single user The main settings of a database can be changed manually at a later stage Database configuration 1s discussed in Section 3 2 ds A SHIPX database 15 a collection of files organized in a folder hierarchy The database contains SHIPX data objects stored on files as well as other files such as input files and result files and other documents that may be located in the file structure The folder names are not always intuitive and to access a certain folder in this file structure it 1s therefore recommended to open it via the Database Browser select Explore from the right click context menu The following sections will give an overview of what is available in a typical SHIPX database 3 2 1 Fleet The fleet 1s a collection of all the ships in the database 3 2 2 Ships Each ship in the fleet consists of the ship hull geometry with related data The ship data includes u Loading conditions
71. bility of the crew to work effectively as well as estimating the likelyhood of a secured object sliding across the deck or topling over As an example The transverse loads on a container can be determined as the LFE times the mass of the container Furthermore if the position of the center of gravity is known the tipping moment can be evaluated P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 5 The absolute longitudinal surge and lateral sway accelerations evaluated by the VERES Postprocessor differ from the LON and LFE 1n that the accelerations are relative to the ship s mean position 1 e horizontal and not parallel to the deck when the ship 1s rolling and pitching For this reason the and LFE should be applied rather that the surge and sway accelerations as seakeeping criteria which are specified by means of horizontal accelerations as these criteria are based on measurements on the ship and are measured in the ship s reference frame P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 6 6 2 SHORT TERM STATISTICS This chapter describes the theory related to the calculation of short term statistics in the VERES Postprocessor When calculating short term statistics the transfer functions calculated in VERES are combined with sea states selected by the user and characterized by a standard wave spectrum which are appropriate for the ocea
72. ch section Number of interpolated offset points on each section Number of hulls Number of mass positions continuous distribution Number of mass points on half ship discrete weights Number of transverse cuts Number of longitudinal cuts Number of foil pairs Program constants The following constants are defined Density of sea water p 1025 kg m Acceleration of gravity g 9 81 m s m 4 0 atan 1 0 27 l May depend on license restrictions P 2004 12 21 Max Value 6 40 12 100 100 80 5 200 5000 50 10 20 MARINTEK SHIPX Vessel Responses Users Manual References P 2004 12 21 7 18 SHIPX Vessel Responses Users Manual 81 MARI NTE K References REFERENCES 1 2 3 4 5 6 7 5 9 10 11 12 13 AARSNES J V Evaluation of viscous damping for two dimensional cylinders Technical Report MT86 0357 MARINTEK 1986 ABBOTT I H AND VON DOENHOFF Theory of Wing Sections Dover Publications Inc New York 1959 CONOLLY J E Rolling and its stabilisation by active fins In RINA London March 1968 CRANE C L EDA AND LANDSBURG A C Chapter LX Controllability In E V Lewis editor Principles of Naval Architecture SNAME 1989 DAHLE E A AND MYRHAUG D Chapter 2 Ship capsize in breaking waves in Fluid Structure Interaction in Offshore Engineering Chakrabarti S K Editor vol 1 of Advances in Fluid Mechanic
73. ck the Unselect All button below the Degree of Freedom list box and select Heave to obtain values for the vertical motions Specify Wave Spectrum Present statistical values as Standard deviation RM E Include mas AMS values in plot legend WERES Fostprocessor Wave Spectrum Spectrum Fiersan Moskaowitz Cancel Wave spreading Long crested seas m Spectrum Parameters Keep Hs constant Significant wave height Hs 14 000 m Pernod range T p 5 000 15 000 sec Number af period 20 t Combinations of Hs and Tp Figure 4 21 The Specify Wave Spectrum dialog 3 Select Short term stat in theWave Environment box and click the Spectrum button This opens the Specify Wave Spectrum dialog see Figure 4 21 4 Select a long crested Pierson Moskowitz wave spectrum and a significant wave height Hs of 4 0 m Further select peak periods between 5 0 and 15 0 seconds and set the number of periods to 20 P 2004 12 21 SHIPX Vessel Responses Users Manual 4 22 MARI NTEK Hands on Introduction to VERES 5 To plot the standard deviation select Standard Deviation RMS in the Present statistical values as pull down menu 6 Click the OK button to go back to the Transfer function Statistics dialog Specify Points Positions VIGIL All point labels Tales One point for all files ads gt VERES astpracessor Edit paint properties Position an the hull A 17
74. d needed in order to make the x axis point towards the bow VEL Vessel velocity R HEAD Wave heading R rad FREQ Wave frequency R RETRANS Real part of complex response RAO R IMTRANS Imaginary part of complex response R The following definitions applv u The structure coordinate system 15 defined relative to AP and the base line with the x axis pointing forwards and the z axis pointing upwards a Angles are given in radians a Lengths are non dimensionalized with respect to LSCALE vessel length in VERES jud A 3 L u Velocities are non dimensionalized as the Froude number V V 4 4 91 Frequencies non dimensionalized as E 4 5 93 RZE mA A j f 1 j J a The motion transfer functions RAOs are defined as the motion amplitude divided by wave amplitude for all responses Q The rotational motions are given in radians hence the motion RAOs will be in rad m The motion transfer functions are given in the hydrodynamic coordinate system defined by TREHYD and RREHYD The real and imaginary parts of the complex motion transfer functions are related to wave elevation at the origin of the hydrodynamic coordinate system Thus in VERES the phase angle gives the phase lead relative to a wave crest at the longitudinal position of the origin 1 e the phase angle gives the phase lead relative to a wave crest at the longitudinal center of gravity P 2004
75. d by a number of offset points which are further interpolated upon in VERES The interpolation algorithm will use constant spacing between the interpolated points on each section The user distributes the points on one half of the hull section and VERES will subsequently mirror them about the centerline plane to give a complete description of the hull section This means that for a monohull half of the hull section needs to be described whilst for a catamaran one of the hulls stretching from the hull side to the center line plane will be required Figure 5 3 1 WL Monohull Catamaran Figure 5 3 Description of the hull offset points The specification of offset points requires consideration of the following factors a The offset points and the straight lines between them should provide a good geometrical description of the section shape 5 Please notice that this is different from the definitions in SHIPX where the sections are labeled from the stern In VERES version 4 0 and later the SHIPX definitions are applied in the VERES user interface as well as in output files error messages etc However the input files are unchanged in order to preserve backwards compatibility P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 5 6 a The contours must be specified sufficiently high up on the hull so that interpolation can be performed with the specified waterline sinkage and trim a Whe
76. d follows directly from Newton s law We can formally write the mass forces due to the harmonic motion mode 7 as F 5 7 where are the generalized mass coefficients Assuming that the vessel is symmetric about the x z plane and that the center of gravity 15 located at 0 O za the generalized mass matrix may be written as M 0 0 0 Mzc 0 U M Mza 0 M 0 5 8 di 0 Mzc 0 l U Isa 0 0 E 0 0 0 Isa 0 TAI Here M is the mass of the vessel 1s the moment of inertia in the jth mode and 164 is the yaw roll product of inertia g4 will vanish if the vessel has fore aft symmetry and 15 otherwise small for conventional ships a Added mass and damping forces and moments The added mass and damping forces are steady state hydrodynamic forces due to forced harmonic rigid body motions when there are no incident waves present The forced motion of the vessel generates outgoing waves and oscillating fluid pressures on the hull surface Integrating these pressures over the wetted surface of the hull gives forces on the body proportional to the body acceleration and body velocity We can formally write the hydrodynamic added mass and damping due to the harmonic motion mode 7 as A ikl k D 5 9 where Ajx and Bjx are the added mass and damping coefficients respectively a Restoring forces and moments When a vessel is freely floating the restoring forces will foll
77. ded resistance and loss of propulsive efficiency Simulation of manoeuvrability of a ship SIMAN TAN Station Keeping Station keeping of a ship in waves wind and current dots under development Table 3 2 Future SuiPX Plug Ins Plugin Function amp O EmPower High Speed Empirical resistance calculation for high speed vessels Planned as an extension of Ship Speed amp Powering Basic Optional Slamming pressure and forces on 2D ship sections FREE Slam2D Panel Generator Panel generator to generate 3D panels on the wetted surface of the hull for hydrodynamic calculations wit FE 3D panel method codes under development Includes the conventional ships part of EmPower Empirical Power Prediction program P 2004 12 21 MARINTEK SHIPX Vessel Responses Users Manual P 2004 12 21 3 19 MARINTEK SHIPX Vessel Responses Users Manual 3 20 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 1 4 HANDS ON INTRODUCTION TO VERES This chapter gives a hands on introduction to the use of SHIPX Vessel Responses by going through the process of importing a ship defining a loading condition and specifying the input needed to perform a ship motion calculation and operability study The example is given in a step by step manner trying to point out features of interrest as they occur section 4 2 gives the intro
78. delines e g as given in 23 In the VERES Postprocessor the following limiting criteria may be specified for any chosen position of the vessel Motions in six degrees of freedom Relative vertical motion Probability of slamming Probability of green water on deck Probability of air exposure Vertical acceleration according to ISO 2631 motion sickness Forces in body fixed coordinate system MII Motion Induced Interruptions MSI Motion Sickness Incidence O O 0 O0 LD O O LU U These options cover the most common limiting criteria considered for different ship subsystems seeTable 6 3 11 23 Table 6 3 Common limiting criteria for different ship subsystems Criteria with regard to Ship subsystem Slam Deck Vert Lat Roll MSI Pitch Heave Vert Rel wetn acc acc vel mot Ship hull Propulsion machinery Ship equipment Cargo Personnel effectiveness Passenger comfort Helicopter Sonar Lifting operations P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 26 In the following paragraphs the following main seakeeping criteria catagories are discussed Comfort and safety for passengers and crew u Safety of the craft and cargo u Operational considerations Passenger and crew comfort and safety The comfort and safety of the people onboard the vessel depends upon the type of imposed motion the duration of the voyage and type of perso
79. dent we can express the probability of the slamming pressure becomes larger than a value p at a specific point on the ship hull as a joint probability of item 1 and 2 1 e 2 E P 1mpact pressure gt p exp E F 6 77 2072 From 6 77 the most probable largest slamming pressure pma encountered in N waves can expressed as i EG los N 6 78 204 where N can be calculated by dividing the time duration of the N encountered waves by the mean Zero upcrossing period of the vertical motions similarily the most probable largest acoustic pressure can be calculated as P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 44 i d stt los 37 6 79 20 LO L where ce is the velocity of sound in water set to 1500 m s in VERES The most probable largest acoustic pressure can be used to find the upper physical limit of the slamming pressure If pmax axceeds this limit the acoustic pressure 1s applied in the calculations In a given sea state Equation 6 77 can also be applied to calculate the probability of slamming to occur In this case a threshold pressure must be specified to define the miniumum pressure that can be characterized as a slam The probability of slamming to occur can also be calculated by specifying a limiting relative velocity Ver often referred to as the threshold velocity for slamming Equ
80. duction to the main program while Section 4 3 presents the Postprocessor Depending on your license VERES is also capable of calculating global wave induced loads The necessary input and your choices related to these computations are described separately in Chapter 5 6 Contents 4 HANDS ON INTRODUCTION TO 4 3 4 Long ferm statistics POTE 4 24 VIURIUS sigar Sid 4 1 43 5 Operabilily limiting boundaries 4 26 4 1 OUTLINE 4 2 4 3 6 Percentage operability ZNA 4 30 4 2 CALCULATING VESSEL RESPONSES IN WAVE em 4 3 4 2 1 Importing the hull lines and define loading condition nn 4 3 4 2 20 Defining a Vessel Response calculation RUM uites 4 5 4 2 3 Defining the vessel geometry 4 6 4 2 4 Selecting calculation method 4 7 4 2 5 Vessel description input 4 7 4 2 6 Running a data check 4 8 4 2 7 Viscous roll damping 4 10 4 2 8 Condition information 4 12 4 2 0 Running the computations 4 12 4 3 POSTPROCESSOR TUTORIAL 4 14 4 3 1 Preparing the data for DOSIDFOGCOSSIHE iss it a d 4 14 4 3 2 Responses in regular waves 4 16 4 3 3 Short term statistics 4 21 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 2 4 1 OUTLINE A typical application of the VERES program is to calculate the ship motions in regular as well as irregular seas The example in this section shows
81. e Calculation Method Strip theory Formulation 2D Calculation Options Monohull Multihull Input Data Vessel Description Condition Info Boll Damping etc Additional Matrices Figure 4 7 The Edit Input part of the main dialog 4 2 5 Vessel description input After selecting a geometry file the main particulars of the vessel must be given in the Vessel Description dialog You can access this dialog by selecting the Edit Input part of the main dialog Figure 4 7 and click the Vessel Description button The dialog should be quite self explanatory The radii of gyration are given relative to the center of gravity see Section 5 3 5 for details GM values can be entered manually by removing the checkmark next to Calculate GM at the bottom left of the dialog The values which are disabled are taken from the loading condition input in SHIPX P 2004 12 21 SHIPX Vessel Responses Users Manual 48 Hands on Introduction to VERES Vessel Description Main Dimensions Vessel Mass Distribution Lop LEG AP 84 950 8 Mass 245899471 tonnes 0 Draught Kadi of Gyration Sinkage B d RH 44 8 331 Cancel Trim att 10 000 deg iss 4200 _Lancel M etacentric Heights H bb 142 000 m Help bd 10 000 Calculate GM Coefficients tar datacheck Block Coefficient w aterplane Area Coett Cw Mid Sec
82. e periods that correspond to this design value The long term responses may be based on a given operability profile see Section 6 3 2 for details if required Thus the design value may be based on short crested seas different heading probabilities and a speed curve defining the vessel speed for different significant wave heights 1f required This design value is then combined with different RAOs to find corresponding regular design waves for a certain vessel speed and heading The results are presented as a plot with design wave height as a function of the wave period The plot includes the theoretical limit of breaking waves which for a regular wave is set to a steepness H A 1 7 where H is the wave height and A is the wave length of the regular wave The lowest For a regular wave the wave length A 1 561 T where T is the wave period P 2004 12 21 SHIPX Vessel Responses Users Manual 6 23 MARI NTE Postprocessor Reference wave height that satisfies the steepness criterion 1s considered to be the recommended design wave and this value is specified in the legend for each curve The above mentioned procedure to find a design wave conforms to the recommendations made by DNV concerning fatigue assessment 7 6 3 2 Operational profile Heading probabilities During a long term period a vessel will meet waves of different headings with certain probabilities This may be due to the weather statistics at the given route
83. e all bilge keel input by setting a breadth equal to zero 10 A text report showing all the entered bilge keel data can be viewed in the SHIPX Plot Program by clicking the Report button 4 2 8 Condition information The final step before performing the actual computations is the description of the wave environment which is specified in the Condition Information dialog Here you can specify the vessel velocities wave frequencies and wave headings to be used in the calculations Condition information for frequency domain simulations Vessel velocities Knots Wave sec Wave headings deg 400 7 Add 000 Add Number af values U is head seas Number of values Number of periods EN 180 deg is following seas OF Cancel Help Figure 4 12 The Condition information dialog The wave periods should be chosen so that the range is sufficient for later short term statistics More points are also needed close to resonant periods for the vessel see comments concerning Figure 4 19 Hint Running the program with only a few headings will help you to find where a better wave period resolution 1s needed The easiest way of entering the wave periods 15 to click the Generate button You can specify a range of periods and the number of periods to be generated and the values will be added to the list of periods 4 2 9 Running the computations When you have completed the input and the data ch
84. e applied for a specified motion point in the VERES Postprocessor The file format 15 PROGVER FILEVER FILETYP 1 DESCRTEXT NUMVEL NUMHEAD NUMFREQ HEAD IHdg IHdg 1 NUMHEAD FREQ IFrq IFrq 1 NUMFREQ do IVel 1 NUMVEL VEL IVel do IFrq 1 NUMFREQ FACTOR IVel IHdg IFrq IHdg 1 NUMHEAD enddo enddo The definitions of the variables are given below Variable Description Type Unit PROGVER Identifies program version I not used for any purpose at the moment FILEVER File version 71 0 I can be applied to preserve backwards compatibilitv if the file format 1s changed FILETYP File type 71 I can be applied to offer other ways to input calibration data later DESCRTEXT Text describing the scatter diagram Char NUMVEL Number of vessel velocities I NUMHEAD Number of wave headings I NUMFREQ Number of wave frequencies I HEAD Wave heading R I FREQ Non dimensional wave frequency 0 Ls g i TES Froude number F V gL R D a FACTOR Calibration factor R LLI The relative motion transfer functions are multiplied with the calibration factor Thus a value of 1 0 means no calibration undisturbed wave a factor lower than one can be applied e g at the stern of a vessel 1 head seas to account for diffraction effects e g in a shadow region behind the ship A factor greater than one can be applied to account for water swell up and diffraction in the bow region e g to calibra
85. e definitions of the variables are given below Variable Description Type Unt DESCRIEXI Text describing the wave spectrum Char NFREQ Number of wave frequencies I NDIR Number of wave directions short crested if gt 1 I IHEADTYP Heading type indicator I 1 counterclockwise 90 is from port standard VERES definition 2 clockwise 90 is from starboard typical for compass directions IFREQTYP Frequency type indicator I 1 rad sec 2 Hz IPRINCIPAL Index of principal wave direction I DIR Wave direction R I deg FREQ Wave frequency R I Hz or rad sec WSPEC Wave spectrum value R LI m s If both IHEADTYP and IFREQTYP are not given old file format both of these are assumed to have a value of 1 The wave directions and wave headings should be given in increasing order The wave directions should be within an interval of 180 relative to the principal wave direction The wave directions are converted to be relative to the principal wave direction when read by the program so the origin of the wave directions is irrelevant P 2004 12 21 SHIPX Vessel Responses Users Manual 7 15 MARI NTEK Appendix 7 2 4 Relative motion calibration file rmc This section describes the file format of the relative motion calibration file which enables the user to calibrate the relative vertical motions between the vessel and the waves at a specific location on the vessel This file can b
86. e following definitions apply 7 10 Unit R R I har R kg m R m s R m R R R R a I I I R _ R rad I I I R _ R _ R _ R z R rad R _ 7 C _ u The structure coordinate system 15 defined relative to AP and the base line with the x axis pointing forwards and the z axis pointing upwards a Angles are given in radians P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK Appendix 7 11 a Lengths are non dimensionalized with respect to LSCALE vessel length in VERES pc A 6 u Velocities are non dimensionalized as the Froude number ae 4 7 u Frequencies are non dimensionalized as 4 8 a The complex transfer functions for the pressures are defined as ncc A 9 p9Ga where p denotes the pressure o 1s the density of sea water g is the acceleration of gravity and 6 1 the wave amplitude a The complex transfer functions for the forces are defined as F i pab La 4 10 a The real and imaginary parts of the complex transfer functions are related to the wave elevation at the longitudinal center of gravity 1 e the origin of the motion and geometry coordinate system Thus the phase angle gives the phase lead relative to a wave crest at the longitudinal position of the origin P 2004 12 21 SHIPX Vessel Responses Users Manual 7 12 MARI NTEK Appendix 7 2 IMPORT EXPORT FILE FORMATS 7 2 1 Mass distribution files Continuo
87. e latest experiences when helping users troubleshoot their problems see Figure 1 7 P 2004 12 21 SHIPX Vessel Responses Users Manual 1 6 MARI NTEK Program Installation ShipX Support Web Microsoft Internet Explorer provided by Runit 5 EJ Ex File Edit Favorites Tools Help tak x EJ f P search Sip Favorites media C lt mm cp 3 gt ShipX Troubleshooting Cin this page you will help on resolving problems Supported Windows Versions with ShipX such as installation and update Reporting Errors zn iS Sues Error 13 Type Mismatch on Windows 2000 Invalid Database Basic information regarding the installation Invalid User Settings configuration and use of Ships can be found In jer ques s ara Shed ARS ava Runtime Installation Supported Windows Versions ships is developed for the Windows NT 2000 sP platform The developers of Ships are using Windows AP as the development platform However out test machines are using Windows 2000 SP2 chipx should also function on the latest Service Packs for Windows MT E We have encountered problems with installations on Windows 2000 without any Serice Packs installed Installation of a Service Pack e g SPZ should solve this problem Reporting Errors If you encounter errors in Ships please send us a description of the error messages and if possible an example of how we can reproduce it In additi
88. e you can click the P ot button to view the spectra you have entered P 2004 12 21 SHIPX Vessel Responses Users Manual 6 8 MARI NTE K Postprocessor Reference Formulation of the JONSWAP wave spectrum According DNV Classification Notes 30 5 28 the spectral density function for the JONSWAP Joint North Sea Wave Project spectrum can be written as 2 E Lu 4 1 SUSE Lp X 9 5 I sup CUN Ww g w L F l T wiry t p 9 The wave spectrum parameters A Spectral parameter generalized Phillips constant g acceleration of gravity ay Wave frequency rad sec Peak frequency 27 T Peakedness parameter o Spectral width parameter o 0 07 for ap lt 6 and o 0 09 for gt o The Pierson Moskowitz spectrum appears for 1 The spectral parameter a 1s computed as F H w Q a 5 l l 0 2877 In 16 g 6 10 5 06 1 0 2877 6 11 where H is the significant wave height A standard value of the peakedness parameter y is 3 3 However a more correct approach is to relate the peakedness parameter to the significant wave height and the peak period 5 for 1 v H lt 3 6 gt 5 75 1 1571 9 for 3 6 lt IH Sos 6 12 P T m FTI ZER 1 for 5 V H In the VERES Postprocessor you can choose either to specify the peakedness parameter y directly or the y value can be calculated fro
89. eakedness parameter y is a function of Hs and Tp See Chapter 6 2 for a discussion on this matter P 2004 12 21 SHIPX Vessel Responses Users Manual 4 24 MARI NTEK Hands on Introduction to VERES 4 3 4 Long term statistics As an example of long term statistics results the vertical accelerations at the bow FP are shown in Figure 4 26 The probability level is presented as a function of the single amplitude of the vertical acceleration weighted over all wave headings An annual wave scatter diagram for the North Sea is applied Area 11 in 14 see Figure 6 7 p 6 19 For further details of the calculation please refer to Chapter 6 3 Long Term Statistics Scatter Data File Scatter Data Info c program Title North sea area 11 Annual files ships plugins eres catter al sea Humber of Ha 10 Range 0 5 3 5 m View Spectrum Number of Tz 8 Range 2 5 10 5 s Present response values as A El Single amplitudes t Double amplitudes where applicable Present probabilities as WERES Postprocessor Probability levels 18 2 ta 18 10 Operational profile Select speeds independently Figure 4 24 The Long Term Statistics dialog To obtain the long term results please note that you have to go through the short term statistics example first and then perform the following steps l In the Transfer functions Statistics dialog select Long term stat in the Wave
90. eased the steel weight can be reduced Further hydrodynamic loads and motions are important from the standpoint of safety of the ship and its crew The SHIPX Vessel Responses Plug In is a SHIPX implementation of the VEssel RESponse program VERES which is intended to be a tool that can be used in early design in defining and evaluating model tests and in obtaining supplimentary results The program calculates Motion transfer functions in six degrees of freedom Relative motion transfer functions Motion transfer functions at specified points Global wave induced loads forces and moments Short term statistics of the above mentioned Long term statistics of the above mentioned Postprocessing of slamming pressures Operabilitv operabilitv limiting boundaries operability diagrams for a given sea state and percentage operability a Time simulations of motions and loads including important non linear effects DOCO DODDO Here motions include displacements velocities and accelerations Please note that the options you have available will depend on what kind of license you have Some modules may require an additional license The program is developed by Norwegian Marine Technology Research Institute P O Box 4125 Valentinlyst N 7450 Trondheim NORWAY http www marintek sintef no Copyright reserved MARINTEK SHIPX Vessel Responses IV Users Manual Tvpographical conventions The following conventions are used here Bold In
91. eck 15 acceptable the main computations can be performed This is done in a similar manner as when running the data check but clicking Full Calculation instead of Data check 1n the top of the main dialog The calculations are started as a separate process and can be monitored in the Process Manager in SHIPX Figure 4 13 P 2004 12 21 SHIPX Vessel Responses Users Manual 4 13 MARI NTEK Hands on Introduction to VERES x gy 4 F Process Description Progress Start Time Elapsed Time Est Time Left Status Vessel Responses in Waves ma 06 01 04 14 25 31 00 00 21 00 00 00 In Progress Name 5 175 Demo Calculation Ship s175 mgf imported Loading Condition Design waterline 2 Process List Figure 4 13 SHIPX Process Manager As each combination of wave frequency wave heading and ship velocity starts the time 1s displayed in the log window of the process accessed by clicking the appropriate tab in the bottom of the Process Manager After running the full calculation result files will be present in the results folder of the Run Please notice the following features when running the computations 1 The percentage completed and estimated time left is shown in the Run Time Information section in the dialog 2 During the computations ie data check or full calculations you can cancel the calculations by richt clicking the entry in the process list and select Cancel 3 You may start several calculations as separa
92. eck in part Ry Check Out Checks out the data from the database so they are available for editing E Reloads the values in the dialog window reads them again from the H Reload amp Refresh database Use this button to read recent changes applied by other users Applies for multi user databases only see Section 3 2 7 for details For multi user databases some additional functions will appear for the objects in the database which regulate locking the data for editing by a single user checking in out data As a multi user database the SHIPX database must support features to prevent different users from modifying the same data simultaneously and to ensure that all users work on the most recent information SHIPX therefore requires the user to check out any object before it is modified Once the modifications are completed the object has to be checked in before other users may change it It is not possible to change an object that is checked out by others but it is possible to view it or perform any operation that does not require changes Check out Check in appears as entries in the context menus in the tree view obtained by right click on database objects and at the bottom toolbar in dialog windows in SHIPX Please notice that objects are not automatically checked in when you exit SHIPX If you are working on an object that has not been checked out you may chose Reload amp Refresh to extract the latest version form the data
93. elation 1s assumed between the responses and the incident wave amplitude This will not be correct in high sea states where slamming and water on deck may occur This also assumes that the hull and should be close to wall sided at the free surface The superposition principle can be used to derive the loads and motions in a sea state Potential theory can be applied The fluid 1s assumed to be homogeneous non viscous irrotational and incompressible However viscous roll damping can be accounted for by means of empirical formulas a The vessel is assumed to be s ender 1 e the length of the hull is much larger than the breadth and the draught a In the traditional strip theory 27 the three dimensional hydrodynamic problem can be reduced to a set of two dimensional strips without interaction between the strips Total forces can be obtained by integrating cross sectional two dimensional forces over the ship s length This means that three dimensional effects are neglected a In the high speed theory 10 interaction from the strips upstream 1s accounted for Total forces can be obtained by integrating cross sectional two dimensional forces over the ship s length The theory therefore denoted as a 2 1 2 dimensional theory a The vessel is symmetric about the centerline a For multihulls interaction effects between the hulls are not accounted for except for catamarans where a high speed theory including hull interaction 1s avail
94. end Deadweights as Import Deadweights dE Import and Append Deadweights kE Loading Condition m Deadweight Hydrostatic e Nates Identficatian Description Full load Displacement weight Identification wL Prismatic coefficient Cp Black coefficient Cb Midship coefficient Floating Postion Longit center of buoyancy LEB rel Calculation method Longit center of buoyancy LEB rel Lpp z Draught at amidships 4 000 m Vertical center of buoyancy YEB Trim aft 0 000 Wetted surface area ship Angle of heel stb 0 000 Wetted surface area transom stem Length of waterline LwL 25 552 M v Breadth of waterline Bw 9000 m water plane area volume displacement 504 216 n Water plane area coefficient Cw Longit center of flotation LCF rel Sea water density 7025 rm Longit center of flotation LCF rel Lpp z Immersion Trim moment Unique loading condition number Shell Plating Shell plating thickness Shell plating in of displacement Transverse metacentric height KMT 4 545 m Longitudinal metacentrie height KML 15 554 m 4 OK 4 Cancel Apply Reset Eig Check In iig Check In amp Close Pid OK 4 Cancel gf Apply Reset Eg check In iig Check In amp Close Figure 3 6 Definition of loading condition 3 2 5 Runs In order to handle input and results the concepts calculations analyses and experiments are all covered by the common concept Run A
95. equency domain The frequency of encounter c 1s the frequency the ship will oscillate with c 1s given from the relation w wo eps 5 5 6 where 0015 the wave frequency U 15 the forward velocity of the vessel and g is the acceleration of gravity Under the assumptions that the responses are linear and harmonic the six linear coupled differential equations of motion can be written 23 Ma FA Bak 4 1 6 5 6 k where are the elements of the generalized mass matrix Ajk are the elements of the added mass matrix Bjk are the elements of the linear damping matrix Ci are the elements of the stiffness matrix Fj are the complex amplitudes of the wave exciting forces and moments with the physical forces and moments given by the real part of Fie Fi and F refer to the amplitudes of the surge sway and heave exciting forces while F4 Fs and F are the amplitudes of the roll pitch and yaw exciting moments respectively 15 the angular frequency of encounter 7k are surge sway heave roll pitch and yaw motion amplitudes respectively The dots stand for time derivatives so that 7 and 7 are velocity and acceleration terms respectively P 2004 12 21 SHIPX Vessel Responses Users Manual 59 MARI NTE Postprocessor Reference The different contributions to the equations of motion are u Mass forces The mass forces are forces due to the mass of the vessel an
96. erage user but might be useful for debug purposes and should always be included when reporting errors 3 3 4 Automatic Update To ensure that all users apply the same latest version of SHIPX the workbench has an automatic update function that may be set up to run automatically at start up SHIPX 15 able to update itself either via Internet ftp http or via Intranet common disk area The program will give notification if new versions of Plug Ins or components become available If the user accepts the The actual settings of where ShipX should look for updates is set in the Launcher ini file inthe Program Files ShipX bin folder The average user should not need to change the settings here as this is set automatically by the ShipX Configuration Manager P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK six 3 14 update the program will update itself automatically For external users this means that the program will use an Internet connection to contact the SHIPX website at MARINTEK Update is Available Choose the software you want then click Get it Now Name 1 1 11 CunentVersion Date New Version Date Size Unselect All Ship Plot Program 3 01 0236 3 01 0238 305 0 KB Update log for Ship Plot Program 18 09 2003 10 08 46 12 02 2004 11 39 19 250KB Initialization file for Ship Plot Program s update log 18 03 2003 10 07 57 23 03 2003 08 52 01 0 0 KB Ships Plot Program Help File 13 09 2003 10 21 3
97. ers to the degree of which the seagoing vessel 1s able to satisfy specified seakeeping criteria The calculation of the operability 1s available in three modes Operability limiting boundaries presented as limiting significant wave heights H as a function of the wave period x y plot or wave heading polar plot a Operability diagram presenting operability contours as a function of speed and heading for a given sea state Percentage operability 21 This approach differs from truncating the scatter diagram as this would result in an increased probability of the waves being within the speed curve since the scatter diagram would be re normalized giving a sum of probabilities equal to 1 0 When the response is set to zero as done in VERES the total probability of the sea states where the vessel has nonzero response will be less than 1 0 thus reflecting the time spent in harbour giving more physically correct results when considering e g return periods of 20 years P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 25 6 4 1 Seakeeping criteria To be able to assess the operational envelope of a craft it 1s necessary to define limiting seakeeping criteria The limiting criteria relate to the safety and comfort of passengers and crew to the safety and capasity of the vessel or to operational considerations Such limiting criteria can be found in national and international rules and gui
98. es Untitl adingCondition Design waterline Ship Demo B Root 4 Propulsor components f Data Check ec Full Calculation Fleet 1 b s A Cal Settings Edit input Notes e Information Settings pan Baile my 24 00 m Name Untitled Breadth overall Boa Bmax 9 00 m e Related documents none aa Details gl Common settings Sea water salinity 3 50 Sea water density 1 025 t r Geometry file Sea water temperature 15 00 C Tank water density 1 000 Tank water temperature 16 50 C Please note If the geometry file is auto generated the Shell plating thickness 2 mm geometry as the bilge keel input in Veres is related to t Shell plating in 2 of displacement 0 40 2 Default speed unit knots Default trim unit metres ae Structural components Geometry File Number of interpolated offset points 45 ok lt Cancel w Apply Reset lt 3 Database Browser ZI BIE sl Process Description Progress Start Time Elapsed Time Est Time Left Status 7 h Vessel Responses in Waves EEEE 10 02 04 12 21 20 00 00 01 00 00 00 Finished Success Name Untitled Ship Demo Loading Condition Design waterline El 5 Mii Hull element generation EEEE 10 02 04 12 19 26 00 00 06 00 00 00 Finished Success Name Demonstration Shin Demn 7
99. g all the criteria the Specify Seakeeping Criteria dialog should look like Figure 4 29 Click OK to return to the Operability Regularity dialog 5 Select 0 in the Select Headings list box and click the Select all button under the Select Criteria list box to include all the criteria in the plot 6 Select Operability limiting boundaries and mark that you want to Plot breaking waves limit in the Select Plot Type box This includes the theoretical limit of breaking waves in the plot 7 Click the Hs Tp range button to access the Set Hs and Tp range dialog see Figure 4 30 Specify 18m for the Maximum Limiting Wave Height and 20 as maximum Tp range Keep the other default values and click OK 5 See Chapter 6 4 for details on the maximum limiting wave height P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 29 Set Hs and Ip range Number af Tp values 20 Tprange from 5 000 ta 120 000 18 000 m Figure 4 30 The Set Hs and Tp range dialog 8 Click the P ot Data button The results should now look like Figure 4 31 5 175 Heading 0 0 2 T RR ER PR ER NE EUN pt Vit LI LZ LL IL _ LZL As ass AM WE NNNM _ AKI IAT el EINE WANN NEAN SENE ES ES a i SENS CONNU eae ALL abe de LAN Le LEI L ef
100. ge complete and estimated remaining time are shown and the log for each process can and should be studied Jobs might also be cancelled or aborted using this manager and the priority of each process may be changed Note that cancelling a job might take some time since some computation programs will run until they reach the next break point This is always the recommended way of stopping a process since aborting a process might cause the system to become unstable bix t E V Task Description Progress Start Time Elapsed Time Est Time Left Status ze A Hull element generation EEEE 19 12 00 10 53 04 00 00 12 00 00 00 Finished Success Name Untitled Ship M1968 Loading Condition Untitled E Waveres calculation L 19 12 00 10 53 16 00 00 16 00 00 00 In Progress Name Untitled Ship M1968 Loading Condition Untitled EN Task List Hull element generation Waveres calculation Figure 3 9 The Process Manager shows active background calculations in the workbench 3 3 3 Log File SHIPX creates a log file each time it 1s started The log file 1s always created using the same name so that the log file from the previous SHIPX session 1s deleted when a new session is started The log file is named c Documents and settings N username NshipxNshipx log on win2000 XP c winnt Profiles lt username gt shipx shipx log on winNT This log file is of no use to the av
101. gnificant wave height 1s the RMS value of relative vertical velocity per meter significant wave height Ver is the critical re entry velocity P 2004 12 21 SHIPX Vessel Responses Users Manual 6 31 MARI NTE Postprocessor Reference If a relative motion calibration file xmc is specified for the motion point in question the relative motion transfer functions will be calibrated before calculating the RMS values g and gy See Section 6 1 4 page 6 4 for details If a two parameter JONSWAP spectrum 15 applied 1 the statistical respose 15 not linear with respect to Hs iteration is performed to ensure that g and gr are calculated with correct H and value Otherwise a unit wave height is applied Equation 6 59 15 derived from the joint probability of air exposure and the exceedance of a critical re entry velocity at which slamming is assumed to occur The critical re entry velocity V is determined depending on the user s choice of criterion Ochi 24 type V 0 0934 gL where g is the acceleration of gravity and L is the ship cr length User specified critical re entry velocity Ver a User specified critical pressure Po which gives V 4 P 5 pk where p is the density cr of seawater and K is the pressure coefficient 6 71 for the point in question If the number of slams per hour is specified as a criterion rather than the probability of slamming the probability of slamming
102. h wave heading or for the sum over all wave headings with equal probability of occurrence of each wave heading in the VERES Postprocessor Calculation of the limiting significant wave height for the different criteria 1s described in the following paragraphs Motions The limiting significant wave height lim S due to the motion criteria 1s calculated directly from the results of the short term statistics The short term statistical value of the response per meter wave height g o H is known from these calculations as a function of the period with vessel speed and wave heading as parameters Thus the limiting significant waveheight as a function of the period for a given wave heading and ship speed is obtained by H T o 6 58 5 g X where o is the limiting value of the motion criteria in question specified by the user If a two parameter JONSWAP spectrum is applied 1 the statistical respose 15 not linear with respect to an iteration is performed to ensure that g is calculated with correct H and v value Otherwise a unit wave height 1s applied Slamming The limiting significant wave height due to the probability of slamming is obtained as suggested by Ochi 24 1 d 2 s Up 2 In P E 3 AK where P 1s the permissible probability of slamming specified by the user d isthe local draft g 1s the RMS value of relative vertical motion per meter si
103. he name will be used as legend text on the plot b Select the Type of criterion from the pull down menu in this case Translation Angular motion c Boxes customized for the criterion type will then appear d Specify the position at which the criterion is to be calculated in the Position pull down menu in this case FP e After filling in the necessary information click the Add button Notice that the name of the criterion appears in the List of criteria box l Note that accelerations are specified in m s 0 159 1 472 m s 2 You may of course specify several criteria at one motion point P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 28 Specify criteria E dit criterion Description tert Type of criterion iv acc at FP 0 15g Translation Angular motion Degree of freedom Study Heave w Acceleration 1 472 statistical property Standard deviation HM 5 Add Insert Modify Remove List of criteria Slamming 3 Move First Green Water 7 T ISO hours ove un M owe Down Cancel Move Last Report Number of criteria Help Figure 4 29 The Specify criteria dialog You have now entered one criterion and can fill in the next starting at a again You may edit a criterion by marking it in the List of criteria and when you are done editing clicking the Modify button After addin
104. he Java virtual machine The installation program will ask you where you want to install SHIPX The default location of Program FilesNSHIPX should be suitable in most cases User s Manuals for the Plug Ins are available online in the HelplDocumentation menu In order to view the online manual a pdf document viewer such as the free Acrobat Reader must be installed on your PC If you do not have such a viewer installed 1 e the manual does not show up when you choose it from the menu you can install Acrobat Reader from the Adobe website at http www adobe com products acrobat or from the installation startup screen if you are installing from a CD The first time you run SHIPX on your computer the SHIPX Configuration Manager will start see next section After this configuration you should be ready to use SHIPX 1 2 SHIPX CONFIGURATION MANAGER The SHIPX Configuration Manager can be started from the SHIPX folder in the Start menu You should use this utility whenever you need to replace your license file e g 1 you have some new license options The first time you run SHIPX on your computer the SHIPX Configuration Manager will start automatically see Figure 1 2 EA ShipX Configuration Tool Step 1 License File In order ta start Ships vou need a license File After receiving the license File From MARINTEK you must use the License File Wizard to install it properly License file information status Mat present L
105. he actual computations The example includes the definition of a new input data set in a step by step manner shows how to run a simple data check and finally how to run the main computations 4 2 1 Importing the hull lines and define loading condition 1 Import the VERES geometry file by selecting the Filellmport menu and select Import from VERES geometry file from the sub menu that appears see Figure 4 2 Locate the file s175 mgfinc Program Files SHIPX PlugIns VERES Examples folder Import From VERES geometry File E Import from Mapa geometr File Import From AutoShip geometry File Import From 4uboHydro geometry File Import From Autocad 3D geometry File Es Import From ShipShape LIN File single ship Es Import from shipshape Project Figure 4 2 File import sub menu 2 Right click the imported ship in the tree view and select Edit Principal Characteristics from the context menu The dialog box shown in Figure 4 2 then appears Change the identification to S 175 and click OK P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES Ship S 175 SIEJEJ aS Import Lightship Weights t Import and Append Lightship Weights Principal Characteristics structural Characteristics Em Ship Model Characteristics m Lightship Weight Nates IdentFication Mame 5 175 Main Characteristics Length overall Loa Length between perpendicula
106. he next step is to configure the Auto Update settings in SHIPX more about this in Section 3 3 4 on page 3 13 Typically you should choose to check for available updates on startup and set the notification level to some In addition you will need to enter your user name and password for the SHIPX website If you are installing SHIPX from a CD you can skip the Auto Update settings for the moment as this can be re configured from the Workbench later but 1f you are installing from the Internet it is important that the correct settings are given at this stage EH Shipx Configuration Tool Step Z a X Auto Update Settings IF vou are connected ta the Internet and would like Ships ta check for updates on startup check the box Mote that a valid user name and password are required Check For available updates on startup Notification Level Total Some None User Information User Name Password Cancel Back gt Finish Figure l 4 SuiPX Configuration Tool Step 2 Auto Update Settings 4 The final step is to update the SHIPX Workbench and install all licensed Plug Ins If you are installing SHIPX via the SHIPX website you should click the Update from Internet button If P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Program Installation 1 4 you are installing from CD or an intranet location you should click the Update from Location button usually the correct
107. heave and pitch results For further reference see the Theory Manual P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Postprocessor Reference 3 11 5 5 VISCOUS ROLL DAMPING In order to predict the roll motions VERES can include viscous roll damping from the hull and from bilge keels The roll equation of motion is be written as Maz Mu Aas B T Bi a BY 2 m n 5 13 Mag Baste Fa where the superscripts P V 1 and V 2 denotes the potential linear and quadratic viscous damping terms respectively This equation is nonlinear due to the quadratic viscous damping term and is solved using an iteration technique A brief summary of the theory for the viscous roll damping follows Further information can be found in the references The following components of viscous roll damping are included 1 VERES Q Frictional damping caused by skin friction stresses on the hull Eddy damping caused by pressure variation on the naked hull Q Bilge keel damping The analysis is carried out for two dimensional cross sections The different components are briefly discussed in the following and their contributions to the linear and nonlinear roll damping coefficients are presented in the Theory Manual For further reference see Aarsnes 1 and Himeno 13 5 5 1 Frictional roll damping The frictional roll damping accounts for the damping caused by skin friction on the
108. his loading condition is always numbered as loading condition no 0 and cannot be deleted The dialog for definition of a loading condition 1s shown in Figure 3 6 This dialog can also be used to modify an existing loading condition choose Edit Loading Condition from the context menu of the relevant loading condition The loading condition is defined by a Loading Condition Number selected from a pull down menu an dentification which typically constitutes DWL WLI WL2 etc and a Description which gives possibilities for further description e g ballast draught fully loaded etc Length of Waterline LwL can be modified 1 e override the automatically calculated value by un cheking the checkbox next to the value and entering a new value This can be relevant e g when the bulb penetrates the sea surface Some of the hydrostatic values such as wetted surface area and transom stern area can also be manually defined in the same way Loading conditions can be deleted duplicated copied to the same ship copied to another ship or moved to another ship Right clicking on the relevant loading condition produces a context menu which shows which reports can be generated for the loading condition P 2004 12 21 SHIPX Vessel Responses User s Manual 3 10 MARINTEK s Leading condition no 1 WL1 Full load T 4 00 m E BS Loading condition no 1 WL1 Full load T 4 00 m EBS an Import Deadweights d Import and App
109. hull For the frictional damping Kato s 19 formulas for turbulent flow are used In full scale the flow may usually be assumed to be turbulent and the frictional roll damping will be nonlinear 5 5 2 Eddy damping This damping component is caused by flow separation at the bilge of the cross section Based on results from forced roll tests for a number of two dimensional cylinders without bilge keels Ikeda et al 15 has proposed a prediction method which is applied in the VERES program P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 5 12 5 5 3 Bilge keel damping Bilge keel damping accounts for the increase in roll damping due to bilge keels The bilge keel damping can be divided into two components a Damping due to normal forces on bilge keels This component represents the drag forces obtained by the bilge keels a Damping due to hull pressure created by bilge keels This component represents the difference in hull pressure with and without bilge keels and can therefore be regarded as an effect of the bilge keels P 2004 12 21 SHIPX Vessel Responses Users Manual 5 13 MARI NTE Postprocessor Reference 5 6 GLOBAL WAVE INDUCED LOADS 5 6 1 Introduction VERES can be applied to calculate wave induced loads in form of global forces and moments on a vessel requires a separate license This chapter describes the application of global wave induced loads in VERES An out
110. icensed to MIA License type MIA Press button to start the license File wizard start License File Wizard Back gt Finish Figure 1 2 SHIPX Configuration Tool Step 1 License file update 1 The first step is to locate the appropriate license file for SHIPX You will receive this license file separately either on a diskette via e mail or on the installation CD in a separate License folder To install or update the license file start the License File Wizard by clicking the Start License File Wizard button P 2004 12 21 SHIPX Vessel Responses Users Manual 13 MARI NTEK Program Installation License Key Update Utility X enze key file inztallationfupdate he location of the new license key file Location of new license key file E sLicense ships Browse This utility will help you with the installation of your license ken file The license ken file with the name zpragram key can be found together with the program installation Please locate this file and click the Update button to apply the specified license key file Figure 1 35 License Key Update Utilitiy 2 To update the license key file click the Browse button and locate the license file shipx key not the one located in the Program FilesNSnurieXMbin l When you have located and selected the file click the Update button and the file will be copied to the correct location on your PC 3 T
111. if the masses are moved farther away from the center of gravity and vice versa It 1s obtained by multiplying the x values the longitudinal positions of the masses by a factor This may result in a new location for LCG Transformation of the radius of gyration in the other motion modes is done in a similar manner P 2004 12 21 SHIPX Vessel Responses Users Manual 522 MARI NTE Postprocessor Reference P 2004 12 21 MARINTEK Postprocessor Reference SHIPX Vessel Responses Users Manual 6 1 6 POSTPROCESSOR REFERENCE This chapter provides the theoretical background for the Postprocessor part of SHIPX Vessel Responses Contents 6 POSTPROCESSOR REFERENCE 6 1 6 1 RESPONSES IN REGULAR WAVES 6 2 6 1 1 Transfer functions 6 2 6 1 2 Definition of phase angles 6 2 6 1 5 Relative motions between the ship and the 6 3 6 1 4 Calibration of relative vertical motions 6 4 6 1 5 Forces in the body fixed coordinate 1 6 4 6 2 SHORT TERM STATISTICS 6 6 6 2 1 Representation of sea states 6 6 6 2 2 Short crested seas 6 12 6 2 5 Short term statistics of the cae 15 6 2 4 Motion Induced Interruptions MII 6 17 6 2 5 Motion Sickness Incidence MSI 6 18 6 3 LONG TERM STATISTICS 6 19 6 3 1 Calculation of long term statistics 6 19
112. ile type which can be either gif jpg wmf or bmp e g logo bmp Each time you start the plot program your logo will be loaded and added to all plots reports A logo bmp file is included in the program installation You can either replace this file or add another file if you are not applying a bitmap bmp file 7 If multiple logo files are present the search order is as follows logo gif logo jpg logo wmf or logo bmp The first file found in this search order will be applied 8 The logo will be scaled down if it is too large If you think the logo is placed too close to the frame in the plot heading you can add some extra white space in your logo file by editing it in a graphical program When exporting plots reports to Microsoft Word the file enclosure doc located in the Program FilesNSHIPXNbin folder is applied as a document template The logo is not exported from the plot program Thus to include your company logo in the exported Word documents you should insert your logo into enclosure doc Do not change anything else in this file as this may make the file invalid for its purpose Always make a backup copy before editing the file 1 5 TROUBLESHOOTING If you for some reason should encounter any problems during installation or while using SHIPX please refer to the Troubleshooting section at the SHIPX website before contacting MARINTEK as you may find useful information there We always try to keep these pages updated with th
113. ility of occurrence of the sea states given in a wave scatter diagram for a certain ship speed and wave heading or weighted over all headings Eqs 6 66 and 6 67 respectively All headings input probabilities Co c c co C c c c HET rel Uperakility in 5 LIT 40 3 JU 4 20 10 7 L J o o a a m e 9 a m TX m c a LL LL uc i H 5 qx sS w P EF FF s g 8 d e i mi LI m P E em e a TT m T ma a a E E P 2 m A GA m gt 5 e CRITERIA 9 peus Ship 32 00kn Froject Derma Wave spectrum Fiersan Moskowiti Long crested seas Moth gea area 11 Annual Figure 6 13 Example plot of percentage operability P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 37 The percentage operability for a certain seakeeping criterion ship speed and wave heading is obtained by NH s NTp Doc X p eH 6 66 el k 1 where f is the percentage operability for a certain wave heading p ship speed and seakeeping criterion and p H lt H mm T is the probability of occurence of a significant wave height in interval j below the limiting significant wave height with a wave period in interval k The percentage operability for a certain seakeeping criterion and ship speed for all headings is found by Ng Op 3 Pop PAD 6 67 i where is the percentage operability for al
114. in Section 5 4 as Dni Me coset Op kale 6 2 Here 77 1s the the motion amplitude per unit wave amplitude and Ois the phase angle The motion transfer functions give the proportion of wave amplitude or wave slope transferred by the ship system into the ship motions The response amplitude per unit wave amplitude is often referred to as the response amplitude operator RAO When the motions are presented as motion transfer functions the motion response in a regular wave of e g 2 meters amplitude wave height of 4 meters can be obtained by selecting the RAO value for a given vessel velocity wave period and heading and multiply with the factor 2 6 1 2 Definition of phase angles The phase angle 6 1n Eqn 6 2 give the phase relationship between the motion and the wave a positive value means that the maximum positive motion occurs 6 w seconds before the maximum wave elevation is experienced at the longitudinal center of gravity Negative values implies that the motion lags the wave elevation Examples A phase angle of 4180 degrees means that the response is opposite of the wave elevation while 0 degrees is in phase with the wave elevation A table presenting typical asymptotic values of the phase angles 1n head beam and following seas is shown below P 2004 12 21 SHIPX Vessel Responses Users Manual 63 MARI NTE Postprocessor Reference Table 6 1 Asymptotic phase angles for long periods The places where
115. is case the probabilities should be given manually as the option headings have equal probability of occurrence will give each heading the same weighting regardless of the input being given from 0 180 or 0 360 or any other heading combinations for that matter Speed curve Speed reduction may be accounted for implicitly in the long term analysis by applying different vessel speeds in the different sea states This may be done by specifying a speed curve where the vessel speed is specified as a function of the wave height The vessel speeds may then reflect the effects of voluntary and involuntary speed loss in a seaway The speed curve also reflects the operation of the vessel in such a way that the largest H value in the curve is the largest applied in the calculations For significant wave heights larger than this the vessel is assumed to be in P 2004 12 21 SHIPX Vessel Responses Users Manual 624 MARI NTEK Postprocessor Reference harbour In this case the response for the sea states above the speed curve range is set to zero An example of a speed curve is given in Figure 6 9 design speed Fe l k reduced speed Vessel speed Significant wave height Hs Figure 6 9 Example of vessel speed vs significant wave height 6 4 OPERABILITY This chapter describes the theory related to the calculation of operability applied in the VERES Postprocessor In this context operability ref
116. is input by giving the transverse positions where the z position is the height above base line and the y position is the transverse position from the centerline To select a section simply click at the section number in the list box The values are then displayed in the upper part of the dialog where they can be edited and the values in the list box can be modified Notice that you only need to know the vertical position z position in advance By clicking the Find Y value button after giving the z value the program automatically determines the y value based on the section geometry Clicking the Modify button updates the value in the list box The Reset button sets the selected sectional data to zero See Eqn 5 5 for definition P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES Bilge keel description Edit sectional data Section no 1 Longitudinal position 61 25 m rel y position of bilge keel z position of bilge keel Breadth of bilge keel Find Y value Reset Modify Bilge keel description Section Ch position Y position Z position Breadth Ren Auto generate Report NOTE Only the coordinates of the sections where the bilge keel breadth is specified are shown Figure 4 10 The Bilge Keel description dialog 8 A simplified procedure for entering a bilge keel can be used by clicking the Auto generate b
117. is not accounted for when calculating probabilities only pressures P 2004 12 21 SHIPX Vessel Responses Users Manual 6 43 MARI NTE Postprocessor Reference 6 6 2 Short term statistics For the short term sea state the probabilitv of the relative velocitv being larger than a certain velocitv v can be expressed as 6 73 assuming that the maxima of the relative velocitv follows the Ravleigh distribution P IVal gt u exp A 6 73 204 2 Peta pra A DIG I gt JU Ga is the variance of the relative velocity and Vr w ea is the transfer function for the relative velocity where dw 6 74 In order for slamming to occur at a specified location two conditions have to be satisfied 1 The location considered must come out of the water 2 The pressure at re entry must exceed a certain value to be considered to be a slam For the first item this means that the relative vertical motion at the same longitudinal position of the ship 1s larger than the vertical distance d from the still water surface to the location in question The probability for the amplitude of the relative motion being larger than d can be expressed as ID PI Nar gt d exp C73 6 75 where P 6 76 is the variance of the relative motion Here the relative motions are calculated without any influence of the ship on the waves Since the relative motion and relative velocity are statistically indepen
118. iterion in frequency domain calculations The MIIs can be thought of as the occation when a crewman will have to stop working at his current task and hold on to some convenient anchorage to prevent loss of balance In order to compare the operational performance of different vessels when no specific deck operation 1s being analyzed Graham 12 has proposed to establish a standard deck operation for comparison purposes This standard operation 15 defined as a one minute operation with a tipping coefficient of 0 25 resulting in the unit MIIs per minute for deck operations criteria Proposed values for different risk levels are shown in Table 6 2 Table 6 2 MII risk levels Graham 12 Risk level MIIs per minute 2 Probable 1 5 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 18 MARI NTE Postprocessor Reference It is suggested 1 12 that deck operations be considered substantially degraded when the incidence exceeds one per minute 6 2 5 Motion Sickness Incidence MSI One approach to calculate the motion sickness incidence MSI as a function of the frequency and acceleration of vertical sinusoidal motion was suggested by O Hanlon and McCauley 26 in 1974 The concept was later refined and a mathematical model was proposed in McCauley et al 21 in 1976 This model has been implemented in VERES and it gives the opportunity to calculate the percentage MSI for a certain exposure time exposure times of 2
119. itial Caps Key names menu names dialog boxes and items that are selected from menus for example Edit menu sub menus for example Start MenulProgram FilesISHIPX Courter File names and paths commands Italics Names of buttons or fields in dialog boxes for example Add New Introduction of new terms P 2004 12 21 SHIPX Vessel Responses MARI NTEK Users Manual CONTENTS CONTENTS 1 PROGRAM INSTALLATION 1 1 INSTALLATION INSTRUCTIONS 1 2 SHIPX CONFIGURATION MANAGER 1 3 HASP DEVICE DRIVER 1 4 COMPANY LOGO IN THE SHIPX PLOT PROGRAM 1 5 TROUBLESHOOTING 2 INTRODUCTION 2 1 2 2 2 2202 20252 2 2 4 Lite 2 2 6 22 7 SHIPX VESSEL RESPONSES VERES OVERVIEW Formulations Roll damping Motion control Short term statistics Long term statistics Operability Time domain calculations 2 3 NEW IN VERSION 4 0 3 SHIPX 3 1 THE SHIPX WORKBENCH 3 1 1 oe 3 1 9 3 1 4 User Interface Plug Ins Using the Database Browser Standard SHIPX dialog buttons 52 THE SHIPX DATABASE Do 22 32 9 3 2 4 2221 3 2 6 27 5 3 3 1 Fleet Ships Hull geometry Loading conditions Runs Common Settings Database configuration SHIPX WORKBENCH UTILITIES Report viewer P 2004 12 21 SHIPX Vessel Responses MARI NTEK Users Manual 2 952 3 3 3 3 3 4 SE 3 4 3 4 1 3 4 2 3 5 Process Manager Log File Automatic Update Program Options HULL GEOMETRY MANIPULATION Edit hull
120. l wave headings given a certain speed and seakeeping criterion 1 is the percentage operability for the ith wave heading and P 5 1s the probability of occurrence of the ith wave heading Figure 2 1 shows the prinsiple calculations performed by VERES to obtain the percentage operability 5 The VERES Main Program calculates the motion transfer functions in six degrees of freedom 6 The VERES Postprocessor combines the motion transfer functions with the specified wave spectra to obtain the response spectra short term statistics 7 The response spectra are combined with the specified seakeeping criteria to obtain operability limiting boundaries 8 The operability limiting boundaries combined with the specified wave scatter diagram are summed up over the sea states to obtain the percentage operability P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK Postprocessor Reference Vessel data Wave spectrum S Transfer Response spectrum R Op lim boundaries Calculated 6 38 Specified by the user Seakeeping criteria Roll 4deg 9 Vert acc 0 15g Slamming 3 Green water 7 Wave scatter diagram Percentage operability Figure 6 14 The prinsiple calculations performed by VERES to obtain the percentage operability P 2004 12 21 SHIPX Vessel Responses Users Manual 6 39 MARI NTE Postprocessor Reference 6 5 FATIGUE ASSESSMENT 6 5 1 Introductio
121. ld format is still supported by the VERES Postprocessor To check if a new or old rel file format is read it simply checks to see if XMTN and ZMTN are specified If they are not specified the old file format is assumed We hope this makes the rel file format more flexible for general ship motion calculations P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK Appendix 7 4 7 1 2 Global wave induced loads re3 This section describes the file that contains output data from global wave induced loads calculations from the VERES program The format of this file 1s OPEN ACCESS SEQUENTIAL FORM FORMATTED GLOBAL WAVE INDUCED LOADS CARDID 1 CARDID 2 CARDID 3 CARDID 4 CARDID 5 RHOSW GRAV LPP BREADTH DRAUGHT LCG VCG MASS R44 R55 R66 R64 IMETH GLMETH IMASS NOXCUT NOYCUT if NOXCUT gt 0 then IXCALFORC i i 1 3 XAXISGL 1 XAXISGL 2 do icut 1 NOXCUT XCUTGL icut enddo endif if NOYCUT gt 0 then IYCALFORC i i 1 3 YAXISGL 1 YAXISGL 2 do icut 1 NOYCUT YCUTGL icut enddo endif NOVEL NOHEAD NOFREQ do ivel 1 NOVEL VEL ivel SINK ivel TRIM ivel XMTN ivel ZMTN ivel enddo do ihead 1 NOHEAD HEAD ihead enddo do ifreq 1 NOFREQ FREQ ifreq enddo do ivelz1 NOVEL do ihead 1 NOHEAD do ifreq 1 NOFREQ if NOXCUT gt 0 then do icut 1 NOXCUT GLFCEL j icut ifreq ihead ivel j 1 3 enddo do deutsl NOXCUT GLMOML j icut ifreq ihead ivel j 1 3 endd
122. le and double amplitude can be presented The kth moment of the response spectrum is defined by My I LET wo Se wo duo k 4 UM 6 44 JU where H A p 1s the transfer function between the wave elevation and the response 7 The transfer functions are given as function of the wave frequency a for a given wave heading and forward speed P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 16 TRANSFER FUNCTION W so T S 09 WAVE SPECTRUM 0 og RESPONSE S 0 SPECTRUM s 0 IHEJT SC o Js f iir st i Figure 6 5 Prinsiple proceedure to obtain the response spectrum Sg and integrating to find the RMS value of the response The statistical properties of the responses may now be calculated from the moments of the response spectra The square root of the zeroth order moment of the response spectrum represents the standard deviation equals the RMS value for linear response expressed as GRZE 6 45 The significant value of the response double amplitude may be calculated from the standard deviation as Ns 40 4 6 46 Expected maximum value E Tnax double amplitude in a sea state with duration T hours can be found by using the Rayleigh probability function as an approximation to the probability density function for the maxima of the responses The single amplitude values
123. le methods are a Continuous mass distribution over the ship length For a monohull where forces along the length of the vessel is of most importance the mass may be described by a continuous mass distribution over the length of the vessel a Discrete weights Here point masses are distributed in space For catamarans this option is the only one available The reason for this being that the transverse weight distribution 1s needed in order to calculate e g pitch connecting moments etc Discrete weights can be applied for both monohulls and catamarans P 2004 12 21 SHIPX Vessel Responses Users Manual 5 14 MARI NTE Postprocessor Reference The mass input will be discussed in detail in Section 5 6 3 The notations for the forces and moments are as follows a Longitudinal distribution of forces and moments transverse cuts Type Direction Notation Longitudinal tension force Force E NM Horizontal shear force Vertical shear force about local x axis Torsional moment Moment about local v axis Vertical bending moment about local z axis Horizontal bending moment The forces and moments are obtained by approaching the cut from the bow a Zransverse distribution of forces and moments longitudinal cuts Type Direction Notation E Horton dow Force y Transv erse tension force Vertical shear force about local x axis Vertical bending moment Moment about local v axis Torsional
124. line of the theory 1s given in Section 5 6 2 The methods available are a Strip theory formulation For a monohull at low or moderate forward speed the strip theory formulation developed by Salvesen Tuck amp Faltinsen 27 can be applied to calculate the forces and moments on the vessel a Direct pressure integration This method is available for all vessel types and speeds VERES has been specifically designed to present not only transfer functions of the global loads as function of the wave period but also to give possibility to investigate the longitudinal or transverse distribution of the loads for a given wave condition The forces and moments are calculated at a set of transverse and or longitudinal cuts which are defined in the following manner a Transverse cuts Cuts parallel to the y z plane at given x positions Gives longitudinal distribution of global loads a Longitudinal cuts Cuts parallel to the x y plane at given y positions Gives transverse distribution of global loads To be able to calculate the torsional and bending moments the positions of a longitudinal and transverse moment axis are defined relative to the baseline and centerline of the vessel The moments will be evaluated at the intersection between the cut and the axis The definition of cuts will be discussed in detail in Section 5 6 3 To be able to calculate the dynamic loads on a vessel a description of the mass distribution must be given Availab
125. location of the NUpdates folder will be located automatically Please notice that this is not just an update but is required to complete the program installation EA ShipX Configuration Tool Step 3 gives access En Cancel lt Back ll Update and Installation of Plug Ins Mow we must ensure that the Ships system running on your computer is the latest available Additionally we must install the Plug Ins that your license file Press button to update From the Internet Update From Internet Press button bo update From custom loaction CD Rom etc Update From Location Finish Figure 1 5 SHIPX Configuration Tool Step 3 Update and Installation of Plug Ins 5 The SHIPX Auto Update Utility is started and all the licensed components will be installed updated on your PC when you click the Get it Now button see Figure 1 6 Update is Available 3 xl Choose the software you want then click Get it Now Name l CumentVemin Date New Version Date Ship Java Type Library New File Ship License Information File 04 02 2002 14 15 16 Ship Java Library New File Ships Java Com Library New Fie Ship Plot Program 301 0131 E vaveres EXE File New File Graphics ZIP archive New File Graphics ZIP archive extractor Java class file New Fie RepGen file conversion utility ProKon New Fie RepGen file conversion utlily Loa2asc New Fie 15 02 2002 13 59 52 08 02 2002 09 17 11 18 02 2002 15 55 23 15
126. ly generated by the wind blowing over an open stretch of the ocean for a period of time and this 1s referred to as wind generated waves with periods usually ranging from 1 0 10 0 sec When the wind dies the energy of the sea state will be transferred slowly to lower frequencies until only very long waves are left 10 100 sec This type of waves are referred to as swell In many ocean areas e g the Heidrun oil field the sea state 1s actually a combination of both swell and wind generated sea meaning that an old sea state in reality an old storm from somewhere else 1s interferring with the developing sea state correct wave spectrum would then have two peaks one at a low frequency and one at a normal frequency The standard spectra are not able to model such sea states which require two peaked spectra In the Torsethaugen model a two peak model 15 introduced for all sea states The wave spectrum is a sum of a primary peak and a secondary peak The input to VERES 15 given by specifying the peak period for the primary peak The primary peak or the highest peak located at 7 1s either generated by local wind fields sea Type I or is a result of swell sea Type II The secondary peak for sea of Type I represents the contribution from swell and for sea of Type II the contribution from local wind For fully developed wind sea the secondary peak vanishes Fully developed sea is represented by a narrow band of 7 for a given H
127. m 6 12 based on the significant wave height and peak period Figure 6 2 shows how y value varies with H and 7 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 9 MARI NTE K Postprocessor Reference Peakedness parameter 3 5 36 3 7 38 39 40 41 42 43 44 45 46 47 48 49 50 5 1 D 5 I p H Figure 6 2 The v value as a function of calculated with 6 12 The spectral moments of general order n are defined as HL WD 6 13 For the JONSWAP spectrum as formulated above the spectral moments mo m and can be approximated by i o m 16 Hs 6 14 L a 6 84 mi cz Gus 6 15 1 Il 4 2 Hiwi 6 16 B AT PAZ The mean wave period 7 and the mean zero crossing period 7 can be calculated from the spectral moments above giving Mo 54 5 21 ZG Nz M m 6849 6 17 5 rT T 20 4 T 6 18 V Mo V wi E Thus if H and 7 or T are specified as input to the two parameter JONSWAP spectrum the corresponding T and y values are found by iteration 18 When vis to be calculated by means of 6 12 we refer to this as the two parameter JONSW AP spectrum as only Hs and a characteristic period 7 T or Ti are specified as input P 2004 12 21 SHIPX Vessel Responses Users Manual 6 10 MARI NTE Postprocessor Reference Formulation of the Torsethaugen two peaked wave spectrum Waves are usual
128. mo where there is an equilibrium between energy input and energy losses To identify wether a given combination of Hmo and 7 represents wind dominated sea Type I or swell dominated sea Type II the following boundary is applied T 66H 6 19 Thus when Tp lt Tf a wind dominated sea model I is applied and when Tp gt a swell dominated sea model Type II 1s applied When a Torsethaugen spectrum model 1s applied with long crested swell the VERES Postprocessor provides an option to specify an offset direction for the swell The wind generated sea can then be short or long crested and the swell part of the spectrum will be applied as long crested from the specified direction relative to the primary wind generated wave direction The spectral model used in the Torsethaugen spectrum is the extended JONSWAP model given by By te 6 20 where Sis the wave energy density E is the wave energy density normalization given by Mo 1 Hu ERZE where f is the spectral peak frequency Hz and 7501s the significant wave height defined by 6 21 44 mo 6 22 mois the zero order moment of the wave spectrum SCfMf 6 23 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 11 MARI NTE Postprocessor Reference Sn fn 1s the distribution of normalized wave energy according to the extended JONSWAP model which can be written as S fn GoA T fau M yr fa 6 24
129. n This chapter describes the theory related to the fatigue assessment part of the VERES Postprocessor The option to calculate fatigue damage is only available when postprocessing general RAO files re5 including stress transfer functions In addition the units applied for the stress transfer functions must be Pa kPa or MPa The stress transfer functions can be obtained e g by using VERES to calculate the ship motions and pressure distribution on the hull and subsequently using VESHIP and a finite element program to calculate the structural responses VESHIP then generates a general RAO file re5 which can be applied for long term statistics and fatigue damage calculations in the VERES Postprocessor When postprocessing a general RAO file Fatigue analysis 1s given as a fourth option below the Long term statistics option on the bottom right in the Transfer functions Statistics dialog see e g Figure 4 17 By choosing the Fatigue analysis option one can specify the related input by clicking the Specify button next to it The Fatigue Analysis dialog 15 very similar to the Long Term Statistics dialog and gives in fact access to much of the same input as given in the latter one This includes specification of scatter diagram speed curve and heading probabilities Changing these settings will also influence subsequent long term statistics calculations In addition to the input of these data one can specify the S N curve the design life 1n
130. n area and operation characteristics of the vessel Short term statistics expresses the behaviour of the vessel in a seaway in terms of statistical properties such as the RMS value or the significant value and may be compared with e g operational demands The two available standard wave spectra as well as the option to include a user defined wave spectrum are described in Section 6 2 1 Short crested seas are discussed in Section 0 and the calculation of result quantities are presented in Section 6 2 3 At the end of the chapter Motion Induced Interruptions and Motion Sickness Incidence are defined Sections 6 2 4 and 6 2 5 6 2 1 Representation of sea states The regular waves on which the transfer functions see Chapter 6 1 are based do not exist at sea The wave amplitude and period vary over time and this is referred to as irregular waves An irregular sea state may be characterized by a standard wave spectrum such as the Pierson Moskowitz the JONSWAP Joint North Sea Wave Project wave spectrum or the two peaked Torsethaugen wave spectrum which are all available in the VERES Postprocessor The wave spectrum expresses the distribution of wave energy which 1s proportional to the wave amplitude squared for different wave frequencies The standard spectra are suitable for different types of irregular sea 1 e different ocean areas The JONSWAP spectrum is assumed to be especially suitable for the North Sea and does not represent a f
131. n from these calculations as a function of the period with vessel speed and wave heading as parameters Thus the limiting significant waveheight as a function of the period for a given wave heading and ship speed 15 obtained by The limiting significant wave height lim lim z O fc H T 6 65 amp fic 23 See Section 6 1 5 for details regarding the definition of LON LFE and VFE P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 34 lim where o is the limiting value of the acceleration force criteria in question specified by the user If a two parameter JONSWAP spectrum 15 applied 1 e the statistical respose 1s not linear with respect to H an iteration is performed to ensure that gg 1s calculated with correct H and value Otherwise a unit wave height is applied Motion Induced Interruptions The limiting significant wave height m due to the MII criteria is calculated by iteration on the significant wave height to find the MII value corresponding to the specified MII criterion value MIIs per minute Motion Sickness Incidence The limiting significant wave height lim 5 due to MSI criteria 15 calculated by iteration on the significant wave height to find the MSI value corresponding to the specified MSI criterion specified by percentage of crew vomiting and exposure time P 2004 12 21 SHIPX Vessel Responses Users Manual MARI
132. n number 1 87 500 x location for section 1 T5 number of offset points 0 280 TI 000 y z for offset point 1 0 110 10 000 y z for offset point 2 0 100 9 000 is 0 200 8 000 Fr 0 350 7 000 s 0 560 6 000 di 0 820 5 000 dj T acp 4 000 dd 1 320 3 000 1 340 2 000 T P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE Postprocessor Reference 1 050 1 000 Fr 0 910 0 750 Ft 0 660 0 500 bt 0 540 0 250 di 0 000 0 130 y z for offset point 15 2 section number 2 83 125 x location for section 2 15 number of offset points Jean qut 11 000 y z for offset point 1 0 960 10 000 y z for offset point 2 0 800 9 000 n 0 670 8 000 ae 5 3 5 of gyration ANE The mass moments of inertia are specified by the radii of gyration about the center of gravity and are transformed by VERES to the motion coordinate system The values are given as input in the Vessel Description dialog The following values are specified Typical values Radius of gyration in roll m 0 30 B 0 45 B Radius of gyration in pitch m 0 20 Lpr 0 30 Lpp Radius of gyration in yaw m 0 25 Lpp 0 30 Lpp Coupled radius of gyration in roll yaw m Typical values for a monohull are given in the last column where is the vessel breadth and Lpp is the vessel length between the perpendiculars The radii of gyration are defined as follows l3 22 AM o mo 2 IS a 22 AM M
133. n seen from the stern the offset points must be given clockwise along the contour starting from the deck and with the last point being at the intersection of the section contour and the centerline Figure 5 3 For bulb sections and fully submerged sections the first point must be at the part of the contour nearest the free surface Normally 20 offset points on each half section will provide an adequate description of the sectional shape and assure that correct added mass and damping coefficients are obtained However when choosing the number of interpolated offset points attention should be given both to the wavelength of the incident waves and the ship speed If the frequency of encounter refer Section 5 2 which is the actual oscillation frequency of the ship is high more elements on each section will be needed 5 3 4 Geometry file The VERES geometry file format looks as follows Text string l Iext string 2 Text string 3 Text string 4 LPP i e the value of Lpp NEW IN VERES VERSION 4 Section number X posltion Number of points y Section number 1 ise ctlon numoer l y Section number 2 Z OecLron number 2z y Section number Number of points z Section number Number of points Next section number Below is an example of the first lines for the S 175 hull with a few comments to the right VERES Geometry file Demo 175 Container Ship Basic design Draught 9 5 m 175 0 Lpp 1 sectio
134. ngton DC Office of Naval Reasearch Dept of the Navy 1964 OGILVIE T F AND TUCK A Rational Strip Theory of Ship Motion Part I Technical Report 013 Department of Naval Architecture The University of Michigan 1969 O HANLON J AND MCCAULEY M E Motion sickness incidence as a function of the frequency and acceleration of vertical sunisoidal motion Aerospace Medicine pp 366 369 April 1974 SALVESEN N TUCK E O AND FALTINSEN O Ship motions and sea loads In Transactions of the Society of Naval Architects and Marine Engineers vol 78 pp 250 287 1970 DET NORSKE VERITAS Environmental conditions and environmental loads Classification Notes 30 5 DNV March 1991 P 2004 12 21 SHIPX Vessel Responses Users Manual 8 3 MARI NTE K References 29 WHICKER L F AND FEHLNER L F Free Stream Characteristics of a Family of Low Aspect Ratio Control Surfaces for Application to Ship Design DTRC Report No 933 1958 P 2004 12 21
135. ns and activities onboard i e crew cruise tourist occasional or regular passengers sex and age distribution Recommended limiting values for various types of motions and voyage durations listed in P 2004 12 21 SHIPX Vessel Responses Users Manual 6 27 MARI NTE Postprocessor Reference Table 6 4 A supplement to using the recommended limiting vertical acceleration values above is the criterion called Vertical acceleration according to ISO 2631 1n the VERES Postprocessor The ISO 2631 standard 18 recommends boundary values for the human tolerance to vibriation The ISO 2631 3 covers vertical vibration in the frquency range of 0 1 to 0 63 Hz periods of 1 6 10 sec In this range motion sickness may occur The limits of the standard are specified in terms of Vibration frequency Vibration magnitude Exposure time O O D U Direction of vibration relative to torso Only the vertical acceleration 1 e head to toe limits are available in the standard However this is considered to be the dominant direction in which severe reactions are caused The ISO standard assumes 10 incidence of motion sickness at the boundary among infrequent travellers of the general public Time of exposure can be chosen to be 30 minutes 2 hours or 8 hours The incidence of motion sickness will of course increase with exposure time When applying the ISO criterion it is important to choose the most severe position s of the vessel 1 e
136. nts the easiest way to select the positions of the transverse cuts 1s by using the Generate button After clicking this button you are asked to enter the lowest and highest cut value 1 e the aftmost and foremost point along the hull where you want a cut Further you enter the desired number of cuts maximum 50 which will be equally distributed from the aftmost to the foremost point If you want just a few cuts you can specify their positions one by one b Finally you have to specify the y and z position of the longitudinal moment axis This is an option only if pressure integration is selected refer Table 5 1 When using ordinary strip theory the longitudinal moment axis is always positioned vertically in the waterline WL and horizontally at the centerline CL of the vessel The specification of the transverse cuts is now completed The longitudinal cuts are specified in a similar manner Mass input To be able to calculate global wave induced loads a specification of the vessel s mass distribution will be needed It can be given as a continuous distribution or by point masses The choice P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK Postprocessor Reference 5 19 depends on what sort of output which is needed The two alternatives can be obtained in the following ways 1 By selecting Continuous mass distribution in the Calculation Options dialog Figure 5 6 This choice means that the mass
137. nts Positions dialog now looks like Figure 4 27 3 Click OK and Exit to return to the Postprocessor main dialog then click the Operability Regularity button to enter the Operability Regularity dialog Select Datasets to Plot Process Select velocities File Label Velocity Select Criteria Criterion V acc at FP O 15q Slamming 3 Green Water t WERES Postorocessor ISO hours ALL criteria Select All Unselect All Select Plot Exit Plot Data Select All Sel special Unzelec All Select Headings Activate Plot Dperabilitp limiting boundaries Hs Tp range Show curve far breaking waves limit File Label Heading efine criteria Plot Type E Wave spectrum Combination af curves in each plot E Al crib one vessel speed heading U t Operability diagram contours c t bilit Select All _Sel special Unselect Al jag age operability Scatter diagram Preferences Figure 4 26 The Operability Regularity dialog 4 Click the Define criteria button to access the Specify Criteria dialog We want to specifiy four seakeeping criteria acc at FP 0 15g at FP Slamming 3 at FP at base line GreenWater 7 at Deck at bow and ISO 2 hours at Bridge The criteria information is entered as follows a Fill in the name of the criterion V acc at FP 0 15g for the first criterion T
138. o endif if NOYCUTs t 0 then do icut 1 NOYCUT GLFCET j icut ifreq ihead ivel j 1 3 enddo d Teut 1 NOYCUT GLMOMT j icut ifreq ihead ivel j 1 3 enddo endif IXCALMOM i i 1 3 IYCALMOM i i 1 3 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Appendix enddo enddo enddo Here Variable CARDIDI LS5 RHOSW GRAV LPP BREADTH DRAUGHT LCG VCG MASS R44 R S R66 R64 IMETH GLMETH IMASS NOXCUT NOYCUT IXCALFORC i IXCALMOM i IYCALFORC 1 IYCALMOM i XAXISGL YAXISGL XCUTGL YCUTGL NOVEL NOHEAD NOF REQ VEL ENER IRIM XMTN ZMTN HEAD FREQ GLECER Description Vessel identifying text Density of water Acceleration of gravity Length between the perpendiculars Vessel breadth Vessel draught Longitudinal center of gravity rel L 2 Vertical center of gravity rel BL Vessel mass Roll radius of gyration Pitch radius of gyration Yaw radius of gyration Yaw Roll radius of gyration Hydrodynamic calculation method I Traditional strip theory 2 High speed theory Global loads calculation method 1 Strip theory 2 Direct pressure integration Type of mass input Continuous mass distribution 2 Discrete weights Number of transverse cuts Number of longitudinal cuts Index showing if the force in direction 1 is calculated for the transverse cuts Index showing if the moment about the 1 axis is calculated for the
139. o minimize the motions of the ship If the loads are decreased the steel weight can be reduced Further hvdrodvnamic loads and motions are important from the standpoint of safetv of the ship and its crew The SHIPX Vessel Responses Plug In is a SHIPX implementation of the VEssel RESponse program VERES which 1s intended to be a tool that can be used in early design in defining and evaluating model tests and in obtaining supplimentary results Contents 2 2 1 2 SHIPX VESSEL RESPONSES VERES 2 2 2 2 OVERVIEW m 2 2 1 Formulations 2 4 2 2 2 Roll damping 2 4 2 2 3 Motion control 2 4 2 2 4 Short term statistics 2 4 2 2 5 Long term statistics 0 2 2 0 Opera billy 2 9 2 2 7 Time domain calculations 2 6 2 3 NEWIN VERSION4 0 221 P 2004 12 21 SHIPX Vessel Responses User s Manual 22 MARI NTE Introduction 2 1 SHIPX VESSEL RESPONSES VERES The study of wave induced vessel responses 1s essential in the design of new ships To optimize the operability of the vessel in a seaway it 1s important to minimize the motions of the ship If the loads are decreased the steel weight can be reduced Further hydrodynamic loads and motions are important from the standpoint of safety of the ship and its crew The SHIP
140. o the operability limit boundary example see Section 4 3 5 and then perform the following steps 1 In the Operability Regularity dialog select Percentage operability in the box and click the Scatter diagram button to enter the Scatter data input dialog Make sure that the scatter file is allan sea this file is located in the c Program FilesNSuieXMPlugInsNVEeRESVExamples folder and that a Pierson Moskowitz spectrum is selected then click OK 2 Select the Sum over all headings equal probability of occurrence option in the Wave Headings pull down menu above the Select Headings list box 3 Click Plot Data to obtain the results in Figure 4 32 The percentage operability plot shows the same trends as the operability limit boundary curves The worst criterion is the vertical acceleration criterion with a percentage operability of 97 while the green water on deck criterion does not affect the operability 10096 operability headings equal prob of occurence Operakility in 96 Slamming 396 ISO 2 hours All criteria Green Water 7 c un e a LL m m gt CRITERIA 175 12 00kn Project S 175 Demo Wave spectrum Pierson Moskowitz Long crested seas North sea area 11 Annual Figure 4 32 Percentage operability for the S 175 hull P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK man Program Reference 5 1 5 MAIN PROGRAM REFERENCE This chapter will provide the
141. of phase angles 6 1 3 Relative motions between the ship and the wave 6 1 4 Calibration of relative vertical motions 6 1 5 Forces in the body fixed coordinate system 6 2 SHORT TERM STATISTICS 6 2 1 Representation of sea states 6 2 2 Short crested seas 6 2 3 Short term statistics of the response 6 2 4 Motion Induced Interruptions MII 0 2 5 Motion Sickness Incidence MSI 6 3 LONG TERM STATISTICS 6 3 1 Calculation of long term statistics 6 3 2 Operational profile 6 4 OPERABILITY 6 4 1 Seakeeping criteria 6 4 2 Operability limiting boundaries 6 4 5 Operability diagram 6 4 4 Percentage operability 6 5 FATIGUE ASSESSMENT 6 5 1 Introduction 6 5 2 S N curves 6 5 3 Fatigue damage 6 6 SLAMMING 6 6 1 Slamming pressures 6 6 2 Short term statistics 6 6 3 Long term Statistics 6 6 4 Summary of input APPENDIX 7 1 OUTPUT FILE FORMATS Ld Motion transfer functions rel kda Global wave induced loads re3 7 1 3 Generalized transfer functions file re5 7 1 4 Dynamic pressure distribution re6 Tu IMPORT EXPORT FILE FORMATS RA Mass distribution files NP Wave scatter diagram files sea 7 2 3 Wave spectrum files wsp 7 2 4 Relative motion calibration file rmc 7 3 DIMENSIONS AND CONSTANTS REFERENCES P 2004 12 21 VII 6 29 6 35 6 36 6 39 6 39 6 39 SHIPX Vessel Responses Users Manual MARINTEK P 2004 12 21 SHIPX Vessel Responses Users Manual 11 MARI NTEK Program Installation 1 PROGRAM
142. of the variables are given below Variable Description Type Unit DESCRTEXT Text describing the scatter diagram Char IFORM Identifies type of wave period I l 1 2 T 3 1 HSTXTYPE Identifies if the H and 7 values are given as I I the middle value of the range 2 the highest value of the range 3 the lowest value of the range NUMHS Number of significant wave heights I NUMTX Number of wave periods I HS Significant wave height R I m TX Wave period R I S NPROB Number of occurence of a sea state R LI An example of a wave scatter diagram input file 1s given below North sea area 11 in Global Wave Statistics Annual 2 1 10 7 Oea 5 124559 09 8x59 25 Deo Vb AD 19 86 94 41 10 2 0 3 49 121 99 40 10 2 l 17 63 73 40 13 4 O 6 21 39 26 10 4 0 2 11 19 14 6 3 0 1 4 9 7 4 1 0 0 2 4 4 2 l 0 0 1 2 2 i l 0 0 O 1 1 1 0 O 0 0 1 1 0 0 P 2004 12 21 SHIPX Vessel Responses Users Manual 714 MARI NTEK Appendix 7 2 3 Wave spectrum files wsp This section describes the file format for user input wave spectrum which enables the user to specify a wave spectrum for use in the short term statistics of the VERES Postprocessor as well as for time domain calculations The file format 15 DESCRTEXT NFREQ NDIR IHEADTYP IFREQTYP IPRINCIPAL DIR iDir iDir 1 NDIR do iFreq 1 NFREQ FREQ iFreq WSPEC iFreq iDir iDir 1 NDIR enddo Th
143. omponents become available P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK six 3 15 3 3 5 Program Options Some program settings can be accessed through the Options Dialog This dialog can be accessed through the Tools menu Here the user interface can be customized colour settings etc and special settings regarding Plug Ins and other Tools such as the Auto Update Utility can be accessed The available settings will vary depending on which Plug Ins you have available Options Environment Auto Update Workspace Check far available updates on startup Processh anager Notification Level Colors Total Flug Iri Tools Some Auto Update sk Mone User Information User Mame myusername Password mypaszword Ced Figure 3 11 Options Dialog P 2004 12 21 SHIPX Vessel Responses User s Manual 3 16 MARINTEK s 34 HULL GEOMETRY MANIPULATION 3 4 1 Edit hull Some basic functionality for manipulating hull geometry is included in SHIPX In addition to import and export of geometry files stations contours and 3D lines might be moved added and deleted The hull lines can be edited by the tools in the Edit Hull menu which can by found by right clicking the hull geometry in the Database Browser clicking the button on the toolbar or selecting the EditlEdit Hull menu Editing includes adding and deleting stations contours and 3D lines as well as editing the point
144. on Ship amp generates a few log files ta help us with the diagnosis These file should always be included when you issue an error report ta ensure efficient prablem salving ships Launcher configuration and log files ci Program Files hipz bin Launcher ini ci Program Files Shipxi bin Launcher log ships system log file an Windows 2000 and Windows XP Documents and settings lt username gt Shipk Shipk log ships system log file an Windows MT ec winnt Profiles lt username gt Shipz Shipk log The files can be sent to Dariusz Fathi marintek sintef no Error 13 Type Mismatch on Windows 2000 We have experienced that some Windows 2000 users experience Type Mismatch errors when opening dialogs in the Ships Workbench where spreadsheet controls are applied This happens if MARINTEK you have used comma as decimal separator on your computer To change this setting go to the Regional Settings in the Control Panel in Windows and change the decimal separator to a decimal G SINTEF point We have not seen this problem on Windows XP computers 8 Internet Figure 1 7 Example screenshot from the Troubleshooting section on the SHIPX website P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK introduction 2 1 2 INTRODUCTION The studv of wave induced vessel responses 15 essential in the design of new ships To optimize the operability of the vessel in a seawav it 1s important t
145. on effects between the two hulls The program offers capabilities of performing calculations in the frequency domain as well as time domain simulations In the time domain simulations non linear effects due to restoring and Froude Krylov forces are accounted for 1 e takes account for the above water hull form for these effects 2 2 2 Roll damping The program can include viscous roll damping from hull friction and bilge keels as well as the effects of roll stabilizing tanks and active roll stabilizing fins 2 2 3 Motion control The program can include the effects from passive free surface roll stabilizing tanks as well as active and passive U tube tanks rudder control and active and passive fins such as roll stabilizing fins and T foils The program can also include the effects from air cushions on Surface Effect Ships To include these effects they need to be included in your license 2 2 4 Short term statistics Short term statistics of the data from the calculations includes Standard deviations significant values Expected maximum in seastate of a given duration e g 3 hours Average of the I nth largest values Response zero upcrossing period Plotting of response spectra DL b DU LU DL The calculations are based on selected standard wave spectra Pierson Moskowitz JONSWAP 2 The Froude number is defined as Fn V VgL where V is the ship speed in m sec g is the acceleration of gravity in m sec and L is the ves
146. on the hull input in SHIPX If for some reason you wish to override this auto generated file you can remove the checkmark in the checkbox to the far right of the geometry file name see Figure 4 6 and specify the geometry file name manually or browse for it by clicking the 25 button Geometry File Geometry file Number of interpolated affset paints v Please note IF the geometry file is auto generated the bilge keel input must be checked after adding removing stations in the ship geometry as the bilge keel input in eres is related to the station number index which may then have changed Figure 4 6 The Geometry File part of the main dialog If you wish to view the geometry file using the SHIPX Plot Program you can click the Gy button after the geometry file name is specified You will then see a section view of the offset points Figure 4 1 shows an example of a geometry file plot P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 7 4 2 4 Selecting calculation method The calculation method is selected in a pull down menu in the Edit Input part of the main dialog In the present example the standard 2D Strip theory formulation of Salvesen Tuck amp Faltinsen is to be applied Figure 4 7 Input Hun Identification T ext Fun SE Ship name sl75 mqf imported VERES 4 00 0 Loading condition description Design waterline ShipX exported data Hull typ
147. ow from hydrostatic and weight considerations The restoring force coefficients are independent of the velocity potential and wave frequency and depend only on the body geometry and mass distribution We may write these force and moment components as Fi 5 10 P 2004 12 21 SHIPX Vessel Responses Users Manual 5 10 MARI NTE Postprocessor Reference where are the restoring coefficients a Linearized wave exciting forces and moments The wave exciting forces and moments are the loads on the body when the body 15 restrained from oscillating and there are incident waves These forces can be divided in two effects One effect 1s the force due to the undisturbed pressure field from the incident waves and the second because the body changes this pressure field These forces are referred to as the Froude Krylov and diffraction forces respectively After having determined these coefficients the equations of motion 5 6 may be solved numerically by a direct equation solver after substitution of 5 11 where 77 is the complex motion amplitude The motion transfer functions are then given by the amplitude 77 and phase angle 6 defined by mt mkacos wt 6 k 1 5 12 For a ship with lateral symmetry 1 e symmetry about the x z plane surge heave and pitch are not coupled with sway roll and yaw Thus any error in the sway roll and yaw motion computations will not affect the accuracy of the surge
148. permissible probability of air exposure specified by the user If the user has specified the permissible number of events per hour rather than the probability the probability can be calculated by 6 60 d is the draught to the user specified position at the considered longitudal location g 1s the RMS value of relative vertical motion per meter significant wave height If a relative motion calibration file xmc is specified for the motion point in question the relative motion transfer functions will be calibrated before calculating the RMS value g See Section 6 1 4 page 6 4 for details If a two parameter JONSWAP spectrum is applied 1 e the statistical respose is not linear with respect to H an iteration is performed to ensure that 1s calculated with correct H and y value Otherwise a unit wave height 1s applied Vertical acceleration according to ISO 2631 motion sickness The limiting RMS value of the vertical acceleration is specified in the ISO 2631 standard as a function of the frequency fi a 21 and the exposure time tex see Table 6 5 To calculate the limiting significant wave height the response spectrum Sa w is divided into freqeuncy intervals corresponding to the tabulated ISO frequencies The RMS values of each interval is calculated by integrating the response spectrum see Figure 6 11 The limiting significant wave height 1s found by 11 7 as the minimum value obtained from the intervals gi
149. probability distribution for the maxima peak values of the response is assumed to be Rayleigh distributed The probability distribution for a given sea state i and wave heading j can then be written gt Fpi FL 1 exp z 6 51 fs Rij where Op 15 the standard deviation of the response for a certain sea state i and wave heading j Further the long term probability of exceeding the response R O R P r gt R is found by O R 1 P R 6 52 Figure 6 8 shows the long term probability of exceedance of the vertical bending moment midship for a container vessel To determine the response for a specified long term probability level iteration 1s applied P 2004 12 21 SHIPX Vessel Responses Users Manual 6 21 MARI NTE K Postprocessor Reference Fitting of Weibull parameters A Weibull distribution 15 found to describe the estimated long term distribution well The fitting of the Weibull distribution to the sum of Rayleigh distribitions in 10 1 1s done by a least square technique for a selected range of probability levels The Weibull distribution is described by h P R 1 exp l 6 53 where R is the response corresponding to a certain probability level is a scale parameter and is a shape parameter also referred to as the Weibull s ope In all long term plots from the VERES Postprocessor the Weibull slope is included in the legend for each curve Vertical bending moment
150. probability level or probability of exceedance In this case the number of response cycles in a long term period e g 20 years can be calculated as 20 365 days year 24 hours day 3600 sec hour N T sec 6 54 where 7 is the average long term response period which is found as a weighted average of the Zero crossing periods of the response all seastates all headings T pu 6 55 j 1 where Tzr 1S the zero crossing period of the response and is the probability of occurrence for a given sea state i combined with heading j In all long term plots from the VERES Postprocessor the long term response period is included in the legend for each curve The probability level of exceedance corresponding to the specified return period is calculated as O R gt 6 56 N Hence when the number of response cycles N is found from 6 54 required probability level of exceedance 1s known and the same procedure as applied in Section 0 can be applied to find the corresponding long term response R Regular design waves The VERES Postprosessor can be applied to find regular waves that correspond to a certain long term probability level design value or return period in years Where neccesssary the program calculates the long term responses based on the mentioned choices and applies the response amplitude operators RAOs for regular waves to find the regular wave height for different wav
151. ptions available depends on calculation method and hull type and are shown in Table 5 1 Table 5 1 Possible selections related to definition of cuts Transverse cuts Longitudinal cuts available axis pos available axis pos Strip Theory monohull at low speed P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Postprocessor Reference 5 18 Specify Transverse Cuts Select positions af cuts Longitudinal moment axis position position 10 000 VER l 3 51 Add z paositian 9 500 m 7 143 10714 Modify 14 296 17 85 Remove 21 429 25 000 28 571 Generate 32 143 EZS 35 714 59 296 ka Number of values 1 Cancel Help The coordinates are related to AF the centerline and the Base Line Figure 5 7 The Specify Transverse Cuts Dialog The procedure of defining cuts can be illustrated by the selection of transverse cuts for a multihull 1 You start by clicking the Calculation options button in the main dialog window The Calculation Options dialog then appears as illustrated in Figure 5 6 and you select global loads to be calculated 2 Under the Global loads options part of this dialog you click the Specify button next to the line Number of transverse cuts 3 You have now entered the Specify Transverse Cuts dialog Figure 5 7 and there are two actions you have to perform a If you wish to study the longitudinal distribution of global forces mome
152. rarily and its position relative to the base line may be specified manually in the user interface To enhance flexibility the user may also specify sinkage and trim relative to the waterline given by the vessel draught A positive trim angle implies that the draught 1s increased at the stern and reduced at the bow Further the sinkage and trim are specified relative to the local coordinate system at Lpp 2 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 9 9 5 3 2 Partitioning of the hull into strips The hull 1s defined by a set of body lines at freely selected longitudinal positions The sections in the geometry file are labeled from 1 starting at the foremost part of the vessel The last section 1s at the aftermost part of the stern A sufficient number of longitudinal sections must be used in order to catch the longitudinal position of incoming waves As a rule of thumb the minimum investigated regular wavelength should be at least five times longer than the distance between the strips Typically approximately 30 sections will be sufficient for most cases When the high speed theory is used care should be taken with respect to the longitudinal distribution of the sections the sections should be as evenly distributed as possible and large variations of the distance between following sections should not occur 5 3 3 Description of sections The cross sections of the hull are specifie
153. realistic relative motions e g behind the ship s stern or to account for water pile up in the bow region deck wetness studies A description of the file format can be found in Appendix 7 2 4 page 7 15 6 1 5 Forces in the body fixed coordinate system When dealing with criteria regarding persons or objects 1n a frame of reference fixed to the ship which is usually the case the accelerations or forces per unit mass in this reference frame must include the gravity forces if there are roll and or pitch motions present We will denote these forces as the Longitudinal Lateral and Vertical Force Estimators since the accelerations can be thought of as forces per unit mass The longitudinal force estimator LON is given by LON z y z m z y z 97 6 6 the lateral force estimator LFE by LFE z y z te t y 2 gna 6 7 and the vertical force estimator VFE bv VFE z y z rpg zr y Z 6 8 where g is the acceleration of gravity It should be noted that the total vertical force is actually 9 g but we are only dealing with the dynamic part in the postprocessor and hence the acceleration of gravity 1s not present in the calculation of VFE One should remember though that the vertical forces are oscillating about a non zero value g as opposed to the LON and LFE This should be accounted for 1f one wishes to calculate the total vertical forces on an object The LFE is important in determining the a
154. reate a Vessel Response calculation Run 4 2 2 Defining a Vessel Response calculation Run Right click the Runs collection below the loading condition in the Database Browser Here you can select New Vessel Response calculation to create a new Run You will now enter the main dialog window for this calculation 2 Give the Run a suitable name in the Settings section of the window In Figure 4 5 we have entered the name S 175 Demo Calculation P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 6 lit Vessel Responses in Waves 5 175 Demo Calculation LoadingCondition Design waterline Ship KE E Data Check Full Calculation Fa Settings lt input n Nates Information Settings Mame 5 175 Demo Calculation Geometry File Geometry file Gy Humber of interpolated offset points v Please nate IF the geometry file i auto generated the bilge keel input must be checked after adding rermowing stations in the ship geometry as the bilge keel input in v eres is related to the station number index which may then have changed ef X Cancel F Apply Reset Big CheckIn gk Check In amp Close Figure 4 5 The Vessel Response calculation main dialog window 4 2 3 Defining the vessel geometry The geometry file of the vessel is specified in the Geometry File part of the main dialog By default SHIPX will auto generate a geometry file for the calculations based
155. response with frequency equal to the frequency of encounter The amplitudes in heave roll and pitch are plotted as a function of the wave period To obtain the results in Figure 4 18 to Figure 4 20 perform the following steps 1 In the Postprocessor main dialog click the Transfer functions Statistics button to enter the Transfer function Statistics dialog 2 Select wave headings 0 30 and 60 by marking them in the Select Headings list box 3 Select heave roll and pitch in a similar manner in the Degree of Freedom list box 4 Select Divided by wave amplitude in the Rotational motions RAO s pull down menu in the Preferences dialog Figure 4 16 5 Click the P ot Data button The three plots are then plotted using the SHIPX Plot Program See Eqn 5 5 p 5 8 for definition P 2004 12 21 SHIPX Vessel Responses Users Manual 4 17 MARI NTEK Hands on Introduction to VERES Select Datasets to Plot Process Select Velacities Options File Label Velocity Study E VERES Degree of Freedom Postprocessor Select All Sel special Unselect All Start new page for each vessel speed TAW Belative Vertical Motions Activate Plot Select Plot Type r plot EE Select Headings Select All Unselect All EW Heading Heading Motion Point Center af Gravity T Preferences Define paints positions Wave Environment Slamming Made ie Regular Waves Modulus t
156. rs Lpp Moulded depth ID Breadth overall Baa Bmax Stern position Aft 1 66 m Additional parameters Rake of keel Bilge radius Rise of floor wee Edit Design Loading Condition Check In BZ Check In amp Close Figure 4 3 Input of Principal Characteristics 4 4 3 Right click the design loading condition for the S 175 ship in the tree view and select Edit Design Loading Condition from the context menu The dialog box shown in Figure 4 4 then appears Change the design draught to 9 5 m and click OK P 2004 12 21 SHIPX Vessel Responses Users Manual 45 MARI NTEK Hands on Introduction to VERES Loading condition no 0 DWL Design waterline T 9 5 Sele is Import Deadweights de Import and Append Deadweights Loading Condition m Deadweight AE Hydrostatics e Nates IdentFicatian Description Design waterline Identification D wL Unique loading condition number Floating Position Calculation method Design draught T m Trim att Angle of heel sth Length of waterline LwL Breadth at design waterline Bwl Volume displacement Outdoor Environment Sea water density Shell Plating Shell plating thickness Shell plating in of displacement 4 OK a cancel gf Apply Reset zig Check In iy Check In amp Close Figure 4 4 Input of loading condition data You have now imported the ship hull lines into SHIPX and defined the loading condition and should now be ready to c
157. ructions for e g long term statistics plots you must have done the short term statistics example Please note This 1s not a general restriction on the postprocessor results from the Postprocessor can be calculated and plotted independently P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 16 VERES Postprocessor Preferences Standard units l 4 Lengths Forces Angles Penods Frequencies Short term G degrees seconds ie rad sec probabilities VERES C US Customary radians Noredimensional Hz x Pastpracessor Mor dimenzional per hour Regular waves Ghort term statistics Set as default Rotational motions Response eles Divided by wave amplitude Response value T Abscissa values Abscissa values Wave period w Peak period Tp w Output destination Cancel iw To Plot Program To plot file MPL Exposure time for MS short term statistics 2 000 Hours iw Translators accelerations divided by acceleration of gravity Program settings Default scatter data directory Figure 4 16 The Preferences dialog 4 3 2 Responses in regular waves Let us first have a look at the motion responses of the S 175 hull in regular waves The motion responses are presented for wave headings of 0 30 and 60 0 is head seas The forward speed is 12 knots The ship has a sinusoidal
158. s d Default trim unit metres 224 Database Browser Figure 3 7 Option for specifying default values for some common variables is included in the database 3 2 7 Database configuration The SHIPX database may be defined such that all users can work on a common database multi user database It is also possible to work with a single user database At present specification of which database to use 1s done by locating the top level folder of the database this folder contains a file called root info To open an existing database locate the database by selecting the FilelOpen Database menu option or choose it from the recent database list at the bottom of the File menu To create a new database select FilelNew Database and browse to an empty catalog where the database should be created You will be prompted for a database name shown at the top level in the Database Browser and to select wether the database should be multi or single user To change the properties of the database at a later stage open the root info file lodated in the database folder There are two parameters that may be of special interest 4 To change the name of the database appearing in the treeview in SHIP X change the text after the Name parameter in the root info file 5 To change a single user database to multi user change the parameter IsMultiUserDatabase to True in the root info file and vice versa to change from multi user to single user
159. s Rahman M Series editor Computational Mechanics Publications DALLINGA Hydromechanic aspects of the design of fin stabilisers In RINA London April 1993 DET NORSKE VERITAS Fatigue assessment of ship structures Technical Report 93 0432 DNV 1996 Rev 6 DET NORSKE VERITAS Fatigue analysis of high speed craft Technical Report 98 XXXX DNV 1998 PRELIMINARY REPORT FALTINSEN O M Sea Loads on Ships and Offshore Structures Cambridge University Press 1990 FALTINSEN O M AND ZHAO R Numerical predictions of ship motions at high forward speed In Phil Trans R Soc Lond A vol 334 pp 241 252 1991 FATHI D E AND WERENSKIOLD P Seakeeping performance manual Technical Report Preliminary MARINTEK Trondheim April 1998 GRAHAM Motion induced interruptions as ship operabilitv criteria Naval Engineers Journal pp 65 71 March 1990 HIMENO Y Prediction of ship roll damping state of the art Technical Report 239 Dept of Naval Architecture and Marine Engineering University of Michigan 1981 P 2004 12 21 SHIPX Vessel Responses Users Manual Q2 MARI NTE References 14 15 16 17 16 19 20 21 22 25 24 25 26 27 28 HOGBEN N DACUNHA N M C AND OLIVER G F Global Wave Statistics Unwin Brothers Limited IKEDA Y ET AL On eddy making component of roll damping force on naked hull Technical Report 00403
160. s in this manual but are included here to give a complete reference on this subject 6 6 1 Slamming pressures The calculations of slamming pressures in VERES assume that the pressure is related to the square of the relative vertical velocity between the ship and the wave and the local hullform This can be expressed as DE sp Cp Val 6 70 where Vp is the relative vertical velocity and is a pressure coefficient depending on the sectional shape especially the local deadrise angle This pressure coefficient 15 a function of time and the maximum value is an important parameter for statistical analysis We express the pressure coefficient for the maximum slamming pressure as Pmazr Val E ORG 6 71 i ze The k factor can e g be calculated for a given pressure panel on a section by the computer code SLAM2D It should be noted that the pressure has an upper limit namely the acoustic pressure Pac due to compressibility effects in the water The acoustic pressure can be calculated as Dac Vr 72 where c is the velocity of sound in the water The main reason to include the acoustic pressure is to avoid unphysically large pressures and the acoustic pressure is therefore included as an upper limit in VERES whenever slamming pressures are evaluated 7 With no air content c varies typically between 1450 m s and 1540 m s In VERES the value of c is set to 1500 m s 26 The acoustic pressure
161. s on each curve This makes it possible to fix errors and do minor changes to the hull lines It is also in principle possible to define the entire geometry but this process is rather tedious in most cases since it involves entering every point on every station and contour Figure 3 12 shows and example from the Hull Input dialog When a station 15 added the shape of the station 1s created by interpolation between the station before and after the new station This interpolation can be chosen to be linear or spline It is recommended to be careful with using the spline interpolation option as it sometimes creates unexpected results AN Hull Geometry Input Ship Demo ILI Stations Contours 3D Lines Stations X position 1 260 WS rou E gra E A POP q E roy a 3 P oy 1 E rm U Pa tul xi J g Bow p oy ra tal Pa Fu a w a a NS j Kal n f Tr E Point class 0 000 m 3 046 m Knuckle point D D10 m Point with no characte 0 097 m Paint with no characte 0 188 m Point with no characti 0 363 m Point with no characte 0 500 m Point with no characte 0 625 m Point with no characte 0 763 m Point with no characte ponn 3081 m Point STINET FALSI 50 40 30 20 10 00 10 20 40 50 0 950 m 3 098 m Paint with no characte g Y position k Z pasition Check In HZ Check In amp Close Figure 3 12 Stations contours and 3D lines can be modified using the Hull Geometry Input dialog P 2004 1
162. s with respect to the global coordinate system are denoted 7 1 72 and 73 where m is the surge 7p is the sway and 75 is the heave displacement Furthermore the angular displacements of the rotational motion about the x y and z axes are denoted 74 775 and 776 for the roll pitch and yaw angle respectively The translatory and rotational displacements are shown in Figure 5 2 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 2 4 Figure 5 2 Sign conventions for translatory and rotational displacements For further reference regarding the definitions for the potential theory see the Theory Manual 5 3 VESSEL DESCRIPTION The vessel geometry in VERES is specified in a geometry file with extension mgf The definitions for the input as well as a description of the geometry file will be given in this chapter In the end of the chapter the definitions for the radii of gyration are given 5 3 1 Coordinate system for the geometry file The vessel description is given in a local coordinate system to preserve compatibility with previous versions of the program The user is provided with a certain degree of freedom in choosing the vertical position of this local coordinate system The origin of the local coordinate system is located at Lpp 2 The z axis 1s pointing upwards and the x axis 1s pointing towards the stern and 1s parallel to the baseline The vertical position of the origin may be taken arbit
163. sed in construction of hull structures Aluminium from Fatigue Analysis of High Speed Craft 8 DNV HSLC S N Curve I Base material Non corrosive environment DNV HSLC S N Curve II Welded joint Non corrosive environment DNV HSLC S N Curve III Welded joint Non corrosive enironment DNV HSLC S N Curve IV Welded joint Corrosive environment The S N curves are applicable for all wrought standard aluminium alloys and temper conditions used for design of aluminium hull structures 6 5 3 Fatigue damage The fatigue damage may be calculated based on the S N fatigue approach under the asumption of linear cummulative damage Miner Palmgren hypothesis When the long term stress range distribution is expressed by a stress histogram consisting of a convenient number of constant amplitude stress range blocks Ao each with a number of stress repetitions n the fatigue damage can be calculated by Miner Palmgren s equation 6 69 where D accumulated fatigue damage k number of stress blocks n number of stress cycles in stress block i number of cycles to failure in stress block i from S N curve In the VERES Postprcessor the number of stress blocks applied 1s 30 The maximum stress range in each block 15 applied in order to be on the conservative side P 2004 12 21 SHIPX Vessel Responses Users Manual 641 MARI NTE Postprocessor Reference The procedure applied to calculate the fatigue damage in
164. sel length between the perpendiculars in m P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK introduction 2 9 and Torsethaugen as well as measured wave spectra and can be performed for long and short crested seas 2 2 5 Long term statistics Long term statistics of the data from the calculations can be calculated based on a specified scatter diagram The long term statistics can be calculated for each wave heading separatelv or with a specified probability of each wave heading A speed curve specifying the vessel speed as function of significant wave height can also be specified 2 2 6 Operabilitv The calculation of operability 1s available in three modes 1 Operability limiting boundaries presented as limiting significant wave heights as a function of the wave period 2 Operability diagram 3 Percentage operability The operability can be calculated based on the following criteria Motions in six degrees of freedom Relative vertical motions Probability of slamming Probability of green water on deck Probability of air exposure Vertical accelerations according to ISO 2631 motion sickness Motion Induced Interruptions MIIs Motion Sickness Incidence MSI 0 E O0 0 E O E P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK introduction 2 6 ful ALA A 1 a E it l d B Po kai lil 4 d zeg win amp Hs
165. stics u Operability Regularity Clicking the Transfer functions Statistics button accesses the Transfer functions Statistics dialog and clicking the Operability Regularity button accesses the Operability Regularity dialog The first dialog see Figure 4 17 allows you to plot transfer functions short term statistics and long term statistics see Secs 4 3 2 4 3 3 and 4 3 4 respectively The other dialog see Figure 4 28 allows you to plot operability limiting boundaries and percentage operability see Secs 4 3 5 and 4 3 6 In both dialogs you have the opportunity to select the velocities headings etc to plot In addition the dialogs gives you access to sub windows where wave spectra motion points wave scatter diagrams operability criteria etc may be specified 7 After having made the preferred selections the results can be plotted in the SHIPX Plot Program simply by clicking the P ot Data button in the Transfer function Statistics or Operability Regularity dialog 8 We are now ready to take a look at some of the results for the S 175 ship First notice that the units on the plots presented in the following can be changed by selecting other options in the Preferences dialog see Figure 4 16 This dialog can be accessed by clicking the Preferences button in the Transfer function Statistics or Operability Regularity dialog windows The examples in the following sections build on each other so that to be able to follow the inst
166. t of this file 1s OPEN ACCESS SEQUENTIAL FORM FORMATTED MOTION TRANSFER FUNCTIONS CARDID 1 CARDID 2 CARDID 3 CARDID 4 CARDID 5 RHOSW GRAV LPP BREADTH DRAUGHT LCG VCG NOVEL NOHEAD NOFREQ NDOF do ivel 1 NOVEL VEL ivel SINK ivel TRIM ivel XMTN ivel ZMTN ivel do ihead 1 NOHEAD HEAD ihead do ifreq 1 NOFREQ FREQ ifreq do l 1 NDOF DOF 1 RETRANS 1 ifreq ihead ivel IMTRANS l ifreq ihead ivel enddo enddo enddo enddo Here Variable Ivpe Unt CARDID 1 5 Vessel identifying text Char RHOSW Density of water R kg m GRAV Acceleration of gravity R m s LPP Length between the perpendiculars R m BREADTH Vessel breadth R m DRAUGHT Vessel draught R m LCG Longitudinal center of gravity rel L 2 R m VCG Vertical center of gravity rel BL R m NOVEL Number of vessel velocities I NOHEAD Number of wave headings I NOFREQ Number of wave frequencies I NDOF Number of degrees of freedom I VEL Vessel velocitv R m s SINK Sinkage at a given velocity R m TRIM Trim at a given velocity R deg XMTN X pos of the motion coordinate system R m rel 1 2 ZMTN Z pos of the motion coordinate system R m relative to BL P 2004 12 21 SHIPX Vessel Responses Users Manual 73 MARI NTEK Appendix Variable Description Type Unit HEAD Wave heading R deg FREQ Wave frequency R rad s DOF Degree of freedom I RETRANS Real part of complex motion RAO R IM
167. ta 145 Export Data 5 333 41 338 42 022 1 355 258 Ga ie Em OF EE mcm In this dialog the mass distribution can either be be imported from a mass file by clicking the Import Data button or it can be typed in manually The continuous mass file will have the suffix m2d whilst the discrete mass file will have the suffix m3d Examples of these file formats are given in Appendix 7 2 1 16 VERES will however read import files with mass points on both sides of the centerline but only the ones on the starboard side will be accepted as input P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE Postprocessor Reference 2 20 The mass distribution can be plotted by clicking P ot button If a geometry file is specified VERES will also plot the longitudinal distribution of still water shear forces and bending moment When a mass distribution is selected it is important that the longitudinal center of gravity LCG equals the longitudinal center of buoyancy LCB computed by VERES Further the total input mass and the calculated mass displacement of the vessel must be equal If there are discrepancies from this the mass distribution can be corrected in the Transform Mass Values dialog Figure 5 9 so that it will match the chosen load condition As an example it 1s seen from Figure 5 9 that consistency between the chosen mass distribution displayed in Figure 5 8 and the load condition
168. tartup i Loaded MTRepGen startup f Loaded Animation Lab Startup f Loaded PanelGenerator startup i Loaded shipspeedAndPoywering StationkKeeping Startup f Loaded strength Assessment structure Cancel Startup f Loaded Waveland VaveRes Startup f Loaded XI Link Startup f Loaded Description Calculate vessel responses motions and global loads Load Behaviour Waves Loaded Unloaded Load on Startup Figure 3 2 The Plug In Manager can be applied to register and select which Plug Ins to be used in the workbench P 2004 12 21 SHIPX Vessel Responses User s Manual 34 MARINTEK s 3 1 3 Using the Database Browser Figure 3 1 shows an example of the SHIPX user interface The tree structure on the left hand part of the window is central in the use of the program see Figure 3 3 This is SHIPX Database Browser which displays the contents of the currently open database in SHIPX Most functions can be selected from context menus in this tree structure activated by selecting a node in the tree view with the mouse and clicking the right hand mouse button Figure 3 5 shows the context menu for ship 1n the database browser Many of the functions can also be activated from the buttons on the toolbar or from pull down menus Buttons and pull down menus act on the on the active object of the correct type in the Database Browser e g the active hull active loading condition or active run of a specific type The ac
169. te SHIPX Runs at the same time If you wish one calculation to finish faster than the others you can try increasing its priority by right clicking the entry in the process list and select the Set Priority option P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Hands on Introduction to VERES 4 14 4 5 POSTPROCESSOR TUTORIAL This section gives a brief description of the Postprocessor This is only meant as an introduction The Postprocessor should be quite self explanatory and contains a number of options for plotting results from Vessel Response calculations 4 3 1 Preparing the data for postprocessing Right click the Runs collection below the loading condition in the Database Browser Here you can select New Vessel Response Postprocessor Project to create a new Run To look at motions and operability select New motions and operability postprocessor project from the sub menu that appears You will now enter the main dialog window for this postprocessor project 2 Give the Run a suitable name in the Settings section of the window In Figure 4 14 we have entered the name S 175 Demo Vessel Responses Postprocessor Motions 5 175 Demo LoadingCondition Design waterline Shi Seles Transfer functions statistics EH aperability Regularity Settings Mame 5 175 Demo Postprocessor setup Get a Result file k 5 175 5 475 Demo Calculation didbirootlFleAG76C7 GEM Ships A848
170. te calculations related to probability of water on deck The calibration 1s a function of vessel speed heading and frequency Within the specified range linear interpolation is applied to obtain values for the correct speeds headings frequencies of the transfer functions Outside the specified range of values in the file a constant calibration factor of 1 0 1s applied 1 e no calibration P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Appendix An example of a relative motion calibration file is given below 3 22 1 0 1 Calibration file stern 3 57 0 15 30 60 90 1 4650 1 8312 2 1975 2 4417 2 7469 3 6626 21 975 0 0 1 00 1 00 1 00 1 00 14 0 1 00 0 90 0 80 0 71 1 0 0 97 0275 0 85 074 o 0 84 0 77 0 83 0 84 1 0 0 62 0 68 0 69 0 95 1 0 0 41 0 40 0 39 0 67 1 0 0 00 0 00 0 00 0 00 0 0 0 150 1 00 71 00 L 00 1 90 343 0 0 68 0 69 0 70 0 63 1 0 0 87 0 76 0 66 0 67 1 0 0 80 0 76 0 73 0 63 1 0 0 62 0270 0 77 0 59 1 40 DBZ OLO Os 3 USZY LAU 0 00 0 00 0 00 0 00 1 0 P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTEK Appendix 7 5 DIMENSIONS AND CONSTANTS Array dimensions The following dimensions apply to the arrays in the VERES program and are therefore to be considered as maximum values in the input to the program Description Number of vessel velocities Number of wave frequencies periods Number of wave headings Number of sections Number of input offset points on ea
171. th a length which is much larger than the ship breadth and draught In addition the change in cross sectional area as function of longitudinal position should be slow Consequently large ship motions and large wave heights will restrict the validity of the results However ship motions obtained by the program show good correlation with experiments even at wave conditions which are outside the limits of the theory Hence the program may be used to investigate a wide range of conditions bearing in mind that the accuracy 1s reduced as the program is stretched to its limits With wave induced we are referring to the dynamic part of the global loads as opposed to the steady global loads which are the loads that are also present in calm water P 2004 12 21 SHIPX Vessel Responses User s Manual 23 MARI NTE K Introduction 2 2 OVERVIEW The SHIPX Vessel Responses VERES program 15 divided in two major calculation utilities A Main Program that calculates the transfer functions for motions and loads frequency domain as well as performs time simulations and a Postprocessor which helps you with reporting and data presentation as well as further calculations based on the transfer functions Figure 2 1 shows the steps required to calculate the percentage operability for a vessel when applying frequency domain calculations 1 The Main Program calculates the motion transfer functions in six degrees of freedom 2 The Postprocessor combines
172. the wave frequency The short term statistics quantities are derived from the moments of the response spectrum The calculation prinsiple is shown schematically in Figure 6 5 Note that the response values are high when the peak frequency of the transfer function is near near the peak frequency of the wave spectrum 1 e when the wave periods are close to the natural period of the response in question PLEASE NOTE In order to calculate the short term statistics of the response it 1s extremely important that the resolution of the transfer function is sufficiently good In addition the transfer function must cover a sufficient range of wave periods especially in the range where the wave spectrum contains most of its energy VIOLATION OF THIS MAY LEAD TO MEANINGLESS RESULTS FROM THE CALCULATIONS OF SHORT TERM STATISTICS The highest wave period should therefore be at least 2 5 3 times the highest peak period The lowest wave period should be selected so that the transfer function value is low This low range is especially important when studying velocities and accelerations The following results are available in the VERES Postprocessor a Standard deviation of the response RMS value a Significant value of the response u Expected maximum of the response a Average of the l nth highest response amplitudes a Response zero upcrossing period a Spectral values wave frequency a Spectral values encounter frequency Where applicable both sing
173. theoretical background for the VERES computer program Further reference can be found in the Theory Manual and citations throughout the text Contents 5 MAIN PROGRAM REFERENCE 5 1 5 1 BASIC 0 0 2 5 2 DEFINITION OF COORDINATE SYSTEMS WAVE HEADING AND MOTIONS 5 3 5 3 VESSEL DESCRIPTION 5 4 5 3 1 Coordinate system for the geometry NIE 3 4 5 3 2 Partitioning of the hull into strips 3 9 5 3 3 Description of sections 5 5 5 3 4 5 6 5 3 5 Radii of gyration S 54 EQUATIONS MOTION 5 8 5 5 VISCOUS ROLL DAMPING 5 11 5 5 1 Frictional roll damping 5 11 5 5 2 Eddy damping 5 11 5 5 3 Bilge keel damping 9 12 5 06 GLOBAL WAVE INDUCED LOADS 5 13 5 6 1 Introduction 5 13 5 6 2 Outline of theOTV 5 16 5 6 5 Input Description 5 16 P 2004 12 21 SHIPX Vessel Responses Users Manual 52 MARI NTE Postprocessor Reference 5 1 BASIC ASSUMPTIONS In short the basic assumptions 1n the VERES program are a The ship is assumed to oscillate harmonically with frequency equal to the frequency of encounter No transient effects due to initial conditions are accounted for No hydroelastic effects are accounted for a A linear r
174. tion Coefficient Cm Please nate the following definitions Longitudinal center of gravity LOG is gwen relative ta AP positive forwards Vertical center of gravity VL is given relative to the baseline Figure 4 8 The Vessel Description dialog 4 2 6 Running a data check 1 After specifying the vessel data you should run a data check which is done by de selecting the Edit Input part of the main dialog e g close all sub dialogs and select the Settings Tab and clicking the Data Check button at the top left of the main dialog 2 After the data check 1s finished the main hydrostatic properties of the vessel are displayed in the SHIPX Plot Program In the data check report the computed values are compared with the values in the Vessel Description dialog The values which are used in the hydrodynamic calculations are marked with The selection of the values are made to ensure consistent input The data shown are also written to a file with the suffix hyd which can be found in the Results folder for the active SHIPX Run 3 If selected in the Calculation Options dialog a geometry output file with suffix str can be created This file shows the interpolated coordinates on the wetted surface of the hull and it can be viewed using the SHIPX Plot Program it 1s automatically shown there after a data check if present The coordinates in this file are the actual hull coordinates used by VERES in the calculations P 2004 12 21
175. tions depend very much on the type of vessel considered Demands from heave compensators on drilling or crane vessels helicopter landings use of sonar use of fishing equipment or danger of cargo displacements are typical examples The list 1s indefinite and the critical values must be evaluated in each case P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE Postprocessor Reference 6 29 6 4 2 Operabilitv limiting boundaries Operability limiting boundaries are obtained in the VERES Postprocessor by combining the results from the short term statistics with seakeeping criteria defined by the user as discussed above Section 6 4 1 When plotting the operability limiting boundaries in the VERES Plot program the seakeeping criteria appear as limiting curves in a diagram with the limiting significant wave height as the ordinate and with the wave period along the abscissa similar to a scatter diagram The vessel meets the seakeeping criteria for the wave height wave period combinations below all the boundary curves The diagram gives information about which significant wave height is critical for the different criteria and which criterion is the limiting one at the different wave periods Demo Ship Heading 0 0 16 14 12 un d 10 gt m B c E W 4 2 5 6 T 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 PEAK PERIOD Tp sec Vert acc at FEF r o 32 U0kn
176. tive object 1s selected by clicking in the Database Browser and is shown underlined in the Database Browser see e g the loading condition in Figure 3 3 To avoid errors and misunderstandings it 15 generally recommended to use right click on the object of choice rather than using buttons and pull down menus at least for inexperienced users A SHIPX database contains SHIPX data objects as well as a file structure where other files such as input files and result files from calculations etc can be stored The top level of the tree view shows which database 1s currently open zu Root By Fropulsor components i gi Fleet 1 Ship Demo ts Loading conditions 1 gik Loading condition na 0 DwL Design waterline T 4 00 m Runs H Motion transfer functions Operability study M vessel Response Calculation Wave Resistance Demonstration gt Design draught 4 000 m Trim aft 0 000 m Volume displacement 503 272 iE Related documents none wae Details ir Length between perpendiculars Lpp 24 00 m lt gt Breadth overall Boa Bmax 9 00 m E Related documents none aan Details Lgl Common settings Sea water salinity 3 50 Sea water density 1 025 trr Sea water temperature 15 00 C Tank water density 1 000 trr Tank water temperature 15 50 amp Shell plating thickness mm Shell plating in of displacement 0 40 amp Default speed unit kno
177. ts amp Default trim unit metres af Structural components Database Browser Figure 3 3 The SHIPX Database Browser P 2004 12 21 SHIPX Vessel Responses User s Manual MARINTEK six 3 5 Several collections appear on first level in the database At present these are Fleet collection of ships Common settings default seawater density etc Propulsor components Structural components A ship can have many loading conditions and each loading condition can have many runs associated with it 99 45 The concept of runs is introduced to cover different terms as calculations analyses and experiments A Run might contain both nput and Results and these can in turns contain single values tables with values or tables with objects In addition information like date and time describing text and version number for the data are stored in a run Changes done to the database are not automatically saved before SHIPX is terminated To avoid accidental loss of data it 15 recommended to store data manually after major changes to the database DatabaselSave click or select Save All by right click on most levels in the tree view It is also possible to save single objects It is possible to apply several databases but only one at a time To change to another database choose FilelOpen Database to select the location of the other database For multi user databases some additional functions
178. ully developed sea It has a peakedness parameter which determines the concentration of the spectrum about the peak frequency The Pierson Moskowitz spectrum is suitable for a fully developed sea 1 e a sea state where the wind has been blowing long enough over a sufficiently open stretch of water so that the high frequency waves have reached equilibrium At this point the waves are breaking slightly In the part of the spectrum where the frequency is greater than the peak frequency 0 gt ap the energy distribution is proporsional with c For a given significant wave height and peak period the Pierson Moskowitz spectrum 15 identical with the Bretschneider ISSC and ITTC spectrum models The Pierson Moskowitz spectrum appears for y 1 m JONSWAP formulation The Torsethaugen spectrum is a two peaked spectrum which includes both wind generated sea and swell An option is included to enable long crested swell from a direction different from the principal wave direction direction of the wind generated waves Figure 6 1 shows JONSWAP spectrum for 71 7 where 1 is equivalent to the Pierson Moskowitz spectrum The concentration of wave energy with increasing easily be seen P 2004 12 21 SHIPX Vessel Responses Users Manual MARI NTE K Postprocessor Reference 6 7 0 050 T 0 045 0 040 7 Figure 6 1 The JONSWAP spectrum for 1 7 The spectrum for y 1 equals the Pierson Moskowitz spectrum
179. us mass distribution m2d 2D MASS DISTRIBUTION Please note the following definitions X position is the longitudinal position rel to Lpp 2 positive aft Z position is the vertical position of local above BL 2D moment of inertia is given about the local Number of mass positions 60 X position Z position 2D Mass 2D Moment m m kg m kg m2 m 62 1080 9 0000 0 000000E 00 0 000000E 00 60 0210 9 0000 0 247619H 04 0 000000E 00 57 9330 9 0000 0 705145E 04 0 000000E 00 Discrete weights m3d 3D MASS DISTRIBUTION Please note the following definitions X position is the longitudinal position rel to Lpp 2 positive aft Z position is the vertical position above BL Number of mass points 145 Mass X position Y position Z position kg m m m 20935201 58 01L909 3 1000 12 1200 136609 7998 5 7 4390 3 1000 16 9000 025042300 95632090 341000 15 4200 P 2004 12 21 SHIPX Vessel Responses Users Manual MARINTEK Appendix 7 13 7 2 2 Wave scatter diagram files sea This section describes the file format of the scatter diagram input file which enables the user to specify any chosen wave scatter diagram for use in the long term statistics of the VERES Postprocessor The file format 15 DESCRTEXT IFORM HSTXTYPE NUMHS NUMTX HS IHs IHs 1 NUMHS ITx 1 NUMTX do IHs 1 NUMHS PROB IHs ITx ITx 1 NUMTX enddo The definitions
180. utton The Generate Bilge Keel dialog shown in Figure 4 11 then appears In this case the bilge keel is specified by a second order polynomial going through three points in the x z plane Thus by specifying the end points as well as a point on the middle bilge keel positions will be automatically generated at each section within the specified longitudinal positions The transverse positions of each point 15 taken by interpolation on each section When you click OK the current bilge keel information will be deleted and new bilge keel data 1s generated Generate Bilge Keel Middle Forward Longitudinal position from AF m 5 23 85 00 36 25 Vertical position from EL m 2 00 li 00 1 10 Bilge keel breadth 10 35 m The bilge keel will be fitted by a polynomial going through the three specified points in the 2 plane The p values are found at each section by interpolation on the station coordinates All previous bilge keel data will be deleted E Lancel Figure 4 11 The Generate Bilge Keel dialog P 2004 12 21 Cancel SHIPX Vessel Responses Users Manual 4 12 MARI NTEK Hands on Introduction to VERES 9 To change the breadth of an already defined bilge keel simply click the Change breadth button You will then be asked for a new value for the breadth and the value will be applied for all defined bilge keel positions 1 e where a non zero bilge keel breadth is defined This option can also be applied to remov
181. years and the fraction of design life in the loading condition represented by the current general RAO file 6 5 2 S N curves The fatigue analysis are based on S N curves describing the fatigue properties of the material 1n use The VERES Postprocessor gives you the opportunity to specify the S N curve manually or to choose from a list of standard S N curves collected from 7 and 8 The input S N curves can be either linear or bi linear where the latter can have a change in slope at a specified number of cycles The basic design S N curve is given as logN loga mlog S 6 66 where N predicted number of cycles to failure for stress range S stress range 40 in MPa m negative inverse slope of S N curve log a intercept of logN axis by S N curve 4 Typically for steel N 10 and for aluminium N 5 10 P 2004 12 21 SHIPX Vessel Responses Users Manual 6 40 MARI NTE Postprocessor Reference The standard curves included in the Postprocessor are Steel from Fatigue Assessment of Ship Structures 7 DNV S N Curve I Welded joint Air Cathodic protection DNV S N Curve Ib Welded joint Air Cathodic prototection DNV S N Curve II Welded joint Corrosive environment DNV S N Curve III Base material Air Cathodic protection DNV S N Curve IIIb Base material Air Cathodic protection DNV S N Curve IV Base material Corrosive environment The S N curves are applicable for normal and high strength steels u

SHIPX Vessel Responses (VERES)

Contents

Download Pdf Manuals

Related Search

Related Contents