1.4.4. Executing SeaFEM solver

1.4.4.1. Automatically executing SeaFEM

SeaFEM solver can be comfortably started through Tdyn preprocessing environment Calculate menu. Once the analyzed problem is defined (i.e. the geometry is created) the boundary conditions assigned, and the mesh is generated, the Start button in the Calculate menu (or the Calculate icon) can be pressed.

Calculate > Calculate window

Then the calculation is started and creates a number of output files (see section Output files for a brief description of the files generated during the execution)

1.4.4.2. Manually executing SeaFEM

Sometimes it can be interesting to run the Tdyn executable (tdyn.exe) manually (without using the graphic user interface of the software) in order to run SeaFEM analysis. The necessary steps are described here.

From here in advance, the following notation will be employed for description purposes:

  • $gidpath : root directory of the installed program. It contains, among others, the gid.exe executable file called to run the GiD custom GUI.

  • $CompassFEM_version : CompassFEM problemtype version name.

  • $inputpath : directory that contains the input data file associated to the SeaFEM model under analysis.

  • $modelname : name of the input data file.

First, the input data file required by the Tdyn executable must be generated before execution. To this aim, the corresponding SeaFEM model must be loaded to the GiD custom interface.

Next, the input data file must be exported, assuming that the model setup has been finished successfully (applying material properties and boundary conditions) and that the mesh has been already generated. In order to export the input file, the following menu sequence must be used:

Files > Export > Calculation file…

By doing this, the user will be asked for a file name ($modelname) and location ($inputpath). By default, .dat extension will be used to export de input file. If desired, .flavia extension can be also specified for instance, trying to mimic the file name convention used when running SeaFEM solver automatically.

Before execution, you must ensure that the tdyn.exe process is able to find a password.txt file containing a valid tdyn password. You can create such a text file manually and copying the password inside. Alternatively, the password.txt file can be copied from the directory $gidpath\problemtypes\$CompassFEM_version\compassfem.gid, where it is automatically saved if tdyn passwords have been previously registered through the GiD custom GUI. For manual execution of the solver, the password file must be located either next to the tdyn.exe executable (this is on the previously mentioned $gidpath\problemtypes\$CompassFEM_version\compassfem.gid\exec directory) or next to the input file.

After exporting the input file and copying a valid password.txt file, everything is ready to launch tdyn.exe manually. To this aim, open a command shell and move to the location of the tdyn.exe executable. Such a location will be typically of the form:

$gidpath\problemtypes\$CompassFEM_version\compassfem.gid\exec

Note that tdyn.exe may be also executed from an arbitrary location if the directory path above is conveniently added to the environment system variable PATH.

Finally, launch tdyn by using the following command line:

C\:> tdyn.exe -name "$inputpath\$modelname" -SeaWaves

1.4.4.3. Output files generated during process execution

The output files described in the following section concern to the global analysis

Output files

Description

ProblemName.flavia.inf

Text file containing global information as well as process information
information for each time step. The content of this file can also
be accessed during calculation through the GUI by using the menu
option Calculate > View process info.

ProblemName.flavia.out

Text file containing iterations and convergence history.

ProblemName.flavia.tim

XML file that contains a timetable in XML format giving information on
the CPU time consumption of the process. The timetable contains a
report of the execution time used by different parts of the problem.
This file is only available after complete successful calculation
of a problem.

ProblemName.flavia.err

Text file containing error messages
(file created only if tdyn.exe exits with an error).

ProblemName.flavia.res

Main results file that contains all field valued results.
When pressing Postprocess in Custom GiD, this file is loaded,
and the results it contains can be visualized in the
post-processing module. Also note that each calculation will

ProblemName.flavia.ram.msh

Mesh for structural analysis using Ram-Series.

The output files described in the following section concern to the results of the mooring system.

Output files

Description

MooringResults.msh

Mesh file containing the nodes coordinates of the mooring
segments mesh for the initial configuration. For
post-process animation,the coordinates of the initial
mesh are updated according to the displacement results
saved in MooringResults.res during calculation.

ProblemName.MooringData.res

Text file containing time evolution data of the tension
force on both ends of each mooring segment.

MooringResults.res

Text file that contains displacement results (components
and module) at mooring mesh nodes. This results are necessary
for animation of the mooring lines in the postprocess.

The output files described in the following section concern to time evolution results on bodies.

Results contained in these files can be visualized using the SeaFEM graphs utility in the SeaFEM Postprocess (see for instance section Results visualization)

Output files

Description

ProblemName.BodyKinematics.res

Text file containing time history data of body movements,
velocities and accelerations of all bodies under analysis.
The complete set of data (all those kinematic results selected
for output in the data tree) is written first for the first
body defined in the GUI. The rest of bodies data results are
written following the order the bodies are defined in the GUI.

ProblemName.BodyLoads.res

Text file containing time history data of body loads and
moments acting over all bodies under analysis.
The complete set of data (all those kinematic results
selected for output in the data tree)
is written first for the first body defined in the GUI.
The rest of bodies data results are written following
the order the bodies are defined in the GUI.
Different components of forces and moments are written
separately. Hence, total forces, reactions, hydrostatic
pressure forces and dynamic pressure forces can be assessed
separately.

ProblemName.Outputs.res

Text file containing time evolution data of the user defined
results. (Up to 10 custom results can be defined by the user
in the User defined data tree entry).

MooringLoads.res

Text file containing time evolution data of
the mooring loads acting on bodies.

The output files described in the following section concern the body animation results

Results contained in these files can be used to setup body animations within the Postprocessor (see for instance section Results visualization).

Output files

Description

ProblemName.BodyMovements_animations.res

Text file containing time history data of the
movements of the first body defined in the GUI
of SeaFEM (referred to the global frame of reference
located at the origin 0,0,0).

BodyMovements_animations_#.res

# stands for an integer index that identifies
the body to which the file under consideration
refers. These are text files similar to the
previous one and concerning the remaining bodies
defined in the analysis.