Wave scatter conversion: Output

To perform the wave scatter conversion you simply click the show regular wave scatter table button which is found on the regular waves page. This command is also available from the action menu. Note that this button is not available if you have a user-specified regular wave scatter table.

The output is presented in a spreadsheet window which, like all such windows in OrcaFlex, can be saved as an Excel file. The spreadsheet is made up of the following sheets:

Sea state table

The input data which specified the sea state scatter table.

Regular wave bins

The regular wave height and wave period bins.

Regular wave scatter table

The main output from the wave scatter conversion – a table listing the number of occurrences of waves in each regular wave bin. Any bins which have occurrences below the occurrence threshold are omitted.

This sheet also displays the total number of bins and the total probability covered by the table. This latter value provides an important check that your bins extend far enough along the wave height and period axes. If is significantly less than 1 then your bins need to be extended.

Automation

Once you have obtained the regular wave scatter table you will usually want to generate a regular wave simulation file for each regular wave bin. There are two options available, determined by the automation method data item:

Text data file: each regular wave bin is mapped to a corresponding text data file. The files are generated when you press the create text data files button.
Batch script: a batch script file is created that will generate a data file for each regular wave bin. The export batch script button can be used to write an OrcaFlex batch script file to automate the generation of these simulation files. Alternatively the create script table spreadsheet button can be used to create a script table spreadsheet which can be pasted into an OrcaFlex Excel spreadsheet.

Base case file name

The name of an OrcaFlex data file on which all the load cases are to be based. This data file should specify a regular wave. The wave height, wave period and simulation duration data will be specified either in the generated text data files, or by the generated batch script file.

If you have already saved the wave scatter data then relative paths can be used when locating this file.

Simulation file name template

Each load case file (corresponding to a single regular wave bin) is given a name based on this template. Special format strings can be used to customise the file names as follows:

%N will be replaced with the load case number. Each load case is assigned a unique number.
%H will be replaced with the wave height for that load case.
%T will be replaced with the wave period for that load case.

The default value of the template is "Case #%N, H=%H, T=%T" and this will lead to files named, for example: "Case #01, H=0.5, T=3.dat", "Case #02, H=0.5, T=5.dat" and so on for all load cases.

Notes:	You do not need to use all three format strings in your template. However, you must use enough of them to make the simulation file names unique. OrcaFlex will display an error message if the simulation file names are not unique.
	Do not specify the file extension as part of the template. OrcaFlex will supply an appropriate file name, either .dat for binary data files or .yml for text data files.

Simulation duration

The durations of the build-up stage and stage 1 for each load case, in terms of the number of wave cycles (different load cases have different wave periods, so we cannot use explicit time durations here).

Override base case log interval and target number of log samples per wave period

These allow you to set the simulation log interval for each load case simulation file by specifying the number of log samples in each wave period instead of defining the absolute length in seconds of the log interval. This allows load cases with longer wave periods to use a longer logging interval than those with shorter wave periods and hence reduce the sizes of the simulation files.

Fatigue

Having generated a regular wave simulation file for each regular wave bin you will commonly want to perform a fatigue analysis. Clicking the export fatigue analysis file button produces an OrcaFlex fatigue analysis file.

This file lists each load case together with the corresponding number of occurrences for that load case. The file produced is not complete and other data, such as the S-N curve data, will need to be added. However, it provides a good starting point for performing the fatigue analysis.

The fatigue line name data item can be used to specify the corresponding fatigue analysis data item.