OrcaFlex 8.4

The latest release of OrcaFlex 8.4 is OrcaFlex 8.4e. To upgrade to OrcaFlex 8.4e, download the following zip file:
OrcaFlex-Patch-8.4a-or-8.4b-or-8.4c-or-8.4d-to-8.4e.zip (1.7 MB)
and then run the program that the zip file contains.

This patch can only be applied if you are currently using an earlier release of version 8.4.

The new features introduced in OrcaFlex 8.4 are described below. For full details please download the following zip file: FlexHelp.zip (956 KB) and save the files it contains. You can then open the saved .hlp file and open the What's New topic in the Introduction chapter of the contents, and follow the links from there to other parts of the help file.

New in Version 8.4e (released March 2004)

Bug fixes

For certain models, the values output in the spectral response reports for vessels contained very minor inaccuracies. This has now been fixed.
Saving data files of models containing winches which use payout rate control specified by variable data was sometimes failing.

New in Version 8.4d (released February 2004)

Shapes

Solid contact force component result variables are now available. Previously just the magnitude of contact force was available.

Bug fixes

The model browser has 2 modes of operation: the "by types" view and the "by groups" view. These modes are intended to work independently of each other. However, moving objects when using the "by types" view was erroneously altering the "by groups" structure.
There was a problem with the results form for multiple statics Offset Graphs. The listbox allowing you to set the offset direction was not being shown.
In some circumstances, the program was unnecessarily repeating Vessel interpolation calculations. This led to increases in simulation run times. This has now been fixed.

New in Version 8.4c (released February 2004)

Lines

Summary and Full Results are now available for flex joints.

Bug fixes

A problem with Windows XP service pack 1 was sometimes causing OrcaFlex to crash. We have added some code to prevent OrcaFlex crashing when this problem occurs.

New in Version 8.4b (released January 2004)

External Functions

The OrcFxAPI DLL functions C_SetDataDouble, C_SetDataInteger and C_SetDataString can now be called from an external function.

Bug fixes

There was an error in the calculation code for the new flex joint modelling objects. The stiffness for flex joints is specified in units of moment per degree of deflection. However, in 8.4a this value was interpreted as if it was specified in units of moment per radian of deflection. The bug only affected flex joints with finite non-zero stiffnesses. That is those flex joints with stiffnesses of 0 or Infinity were unaffected.

New in Version 8.4a (released December 2003)

Distributed OrcaFlex

Distributed OrcaFlex is a suite of programs that enables a collection of networked, OrcaFlex licensed PC's to batch run OrcaFlex jobs, transparently, using spare processor time. We have been using the program in house for some time now and have just released it to customers. For more details, and to download Distributed OrcaFlex please click here.

Simulations

Results from unstable simulations can now be examined and the simulation files can now be saved. If a simulation becomes unstable the simulation is aborted and the program moves to the simulation unstable model state. From this state you can view replays, extract results, save the simulation or return to reset state. If you are operating in batch mode then the unstable simulation is saved and you are notified that there was a problem when the batched calculations are complete.

Environment

Wind loading can now be applied to Lines and 6D Buoy Wings. Previously Vessels were the only objects which responded to wind loads.
Wind speed can now be varied with vertical position. This allows you to model a vertical wind speed profile.
A seabed profile arclength calculation has been added to the environment data form. This calculates the arclength between 2 points along a profile seabed.
Current speed and direction variation can now be given by an external function.

Lines

A new Line Length Wizard has been added. Intended for mooring analyses, this wizard adjusts line length to achieve a specified top tension or top declination.
A Line Clashing Report has been added. This produces a detailed tabular report about the line clashing events during a simulation.
A new type of line attachment for use when modelling flex joints has been added.
You can now define a contact pen which is used when drawing nodes and segments which are in contact with the seabed, elastic solids and other lines.
Line curvature results are now reported when bend stiffness is zero. Previously the curvature was reported as zero when the bend stiffness is zero.
Line expansion factor was previously forced to be 1 during statics. This restriction has been lifted.
When the model is in Statics Complete state the Full Results tables for lines now contain detailed reports of the shortest natural periods.
Catenary convergence parameters can now be set to default values by clicking a button on the line data form.
The behaviour of the Use Calculated Positions button has been altered. If you use this facility in a model which includes lines then you are offered the option of changing the lines' Step 1 Statics Method to User Specified.
In previous versions of the program this data change was only performed for those lines whose Step 2 Statics Method was set to Full Statics. In this version of the program the data is changed for all lines in the model.
A small improvement has been made to the way damping is implemented at line ends. This may give slight changes in results.

Vessels

The Vessel RAO response reports can output RAOs using Orcina standard conventions. Previous versions of the program reported RAOs using the same RAO conventions as specified for the vessel's type. There is a tickbox on the Vessel RAO response form which allows you to control which conventions are used.
The Vessel connections report has been improved. It now includes individual connection forces for Shapes and 6D Buoys. It also includes vertical component and force declination for all connections (previously these were only reported for Lines).
RAO graphs are now ranged automatically to avoid parts of the curve disappearing off the edge of the chart.

Buoys

Spar Buoys and Towed Fish can now be drawn using circular cylinders.

Fatigue Analysis

The rainflow damage calculation has been slightly modified. OrcaFlex scales the single-occurrence load case damage values to allow for the exposure associated with that load case. In previous versions OrcaFlex assigned the damage to the entire simulation period being analysed. Now it is assigned to just the period of time between the first and last extrema of the stress time history. In previous versions of the program, any stress variation between these extrema and each end of the time history made no contribution to damage.
This change makes the program more accurate. For rainflow analysis you need to use a large simulation period in order for the results to be statistically significant. Thus for suitably long duration simulations this change to the calculation will have little effect.

Post-processing

The Results spreadsheet has been renamed as the OrcaFlex Spreadsheet. The "Process All" and "Process Selected" buttons have been removed from the instructions sheet and moved to the new Orcina menu. This new Orcina menu appears in the main menu of Excel.
The OrcaFlex Spreadsheet now has a facility for automating the production of batch script files for a regular set of cases.
New commands called Spectral Density, Empirical Distribution and Rainflow Half Cycles have been added to the OrcaFlex Spreadsheet.
OrcaFlex Spreadsheets can now be handled by the batch processing mode. To use this facility the spreadsheet must have been created from the spreadsheet template from version 8.4a or later.
OrcaFlex Spreadsheets range graph arclengths can now be specified as all arclengths less than or all arclengths greater than. This is done using arclength ranges such as "<35" or ">60".
There is a new command on the OrcaFlex Spreadsheet called OrcFxAPI version. This outputs the version of the OrcFxAPI DLL which is being used by the spreadsheet.

Interface

There is a new Move Selected Objects Wizard which allows you to move a number of objects en masse. This can be found by selecting an object in the model browser and clicking Move Selected Objects on the browser's edit menu (also available from the popup menu). The wizard is most useful when you select multiple objects, a group or a number of groups or even the entire model.
The replay form now accepts '~' for replay interval. This is interpreted as 'use the actual sample interval', i.e. the smallest possible interval.
Stress and pressure values are now labelled in kPa or MPa if the chosen units system correspond to either of these units. For example values which would previously been labelled kN/m^2 are now labelled kPa. Similarly values which would previously been labelled N/mm^2 are now labelled MPa.
In addition a new force unit (MN) has been added. If you choose this force unit together with a length unit of m then stress and pressure values are labelled MPa. This is particularly useful for the Fatigue units selection.
A Set Process Priority form has been added. This allows you to change the processing priority of OrcaFlex. This could be useful if you wished OrcaFlex to run as a background process, for example. The form is accessed from the Tools | Set Process Priority menu item.
New command line switches have been added which allow you to set the process priority when starting OrcaFlex.
If you have installed the Orcina shell extension you will be able to see thumbnail views of data and simulation files in Windows Explorer. This only works with files written by this version or later. Please note that thumbnail views may not be available in some older versions of Windows. Thumbnails views can be displayed by selecting Thumbnails from the Windows Explorer View menu.

OrcaFlex Programming Interface

New functions C_GetWaveComponents, C_AVIFileInitialise, C_AVIFileAddBitmap, C_AVIFileFinalise, C_GetSimulationDrawTime, C_SetSimulationDrawTime, C_CreateTimeHistorySummary, C_GetTimeHistorySummaryValues and C_DestroyTimeHistorySummary have been added to the OrcaFlex Programming Interface. For details please refer to the OrcFxAPI help file.

External Functions

A new DataSourceName field has been added to the TExternalFunctionInfo data structure. For more details see the OrcFxAPI help file.

Bug fixes

The OrcaFlex Spreadsheet was previously ignoring clearance line name.
Attached buoys with wings were failing to use external variable data when the master buoy's wings used external variable data.