Program Layout

The program system consists of five programs or modules communicating via a file system as shown below.

sgd tbl a

A complete dynamic analysis must include running the modules STAMOD and DYNMOD. Post processing or export of results is done by OUTMOD or alternatively S2XMOD. However, an efficient data base system simplifies the work during the analysis by storing input data and intermediate results.

The layout of the program system is presented in the figure below. Each module will be further detailed in the following.

layout prog mods
Figure 1. Layout of the SIMO program system and file communication between modules

1. STAMOD, initial condition and static equilibrium

The purpose of the module is to define the initial condition for the dynamic simulation. The description of the system to be simulated is read from a file, SYSFIL.

Selection between environmental conditions can be done.

A static equilibrium position may be calculated with average environmental forces applied. Natural periods and oscillation modes of the system may be calculated.

The initial conditions are written to the file INIFIL for use by DYNMOD.

2. DYNMOD, dynamic response calculation

The purpose of the module is to calculate responses in the time domain. Before starting time integration of the equation of motion, the various simulation parameters must be initialized.

3. S2XMOD, export of time series

The purpose of the module is to export result from dynamic analysis, i.e. time series to various file formats. In present version export to MATLAB ("m"-file), export to ASCII-file and export to DIRECT ACCESS file are available. In addition the module provides simple statistics and plot of time series.

4. SimVis, 3D visualization program

Stand-alone program for 3-dimensional visualization of static and dynamic analysis, based on GLView.

5. File system

When running the SIMO modules, different kind of files are needed. Each module communicates to terminal (or reads a macro file) and generates output on the print file.

The system description file, SYSFIL, contains a description of bodies, couplings and environmental data. It is a symbolic data file which is read by STAMOD.

The initial condition file, INIFIL, is generated by STAMOD. If only modifications to an already defined initial condition are required, STAMOD can also read INIFIL. DYNMOD reads INIFIL to fetch the system to be simulated.

The pregenerated data file, PREFIL is used for internal storage of simulation parameters in DYNMOD.

The time series file, TSFIL, contains all time series. It is generated by DYNMOD.

The default file name system utilizes the system identifier and initial condition identifiers, chsys and chini. Both contain up to 8 characters. At the beginning of each module, it is asked if default file names should be used. The default file names will be:

File type Short name File name syntax Example, chsys=s1, chini=i1

System description file

SYSFIL

sys[- chsys].dat

sys-s1.dat

Initial condition file

INIFIL

ini[- chsys[- chini]].sam

ini-s1-i1.sam

Print from STAMOD

PRSFIL

prs[- chsys].lis

prs-s1.lis

Print from DYNMOD

PRDFIL

prd[- chsys[- chini]].lis

prd-s1-i1.lis

Pregenerated data file

PREFIL

pre[- chsys[- chini]].sam

pre-s1-i1.sam

Time series file

TSFFIL

tsf[- chsys[- chini]].ffi

tsf-s1-i1.ffi

6. Running SIMO

SIMO is normally started by typing simo at the command line prompt in the operating system. The system then typically responds by:

 **********************************************************
 *   WELCOME TO                                           *
 *                                                        *
 *    SSSSSSSSSS    III   MMMMM    MMMM      OOOOOOOO     *
 *   SSSSSSSSSSSS   III   MMMMM   MMMMM     OOOOOOOOOO    *
 *   SSS            III   MMMMMM MMMMMM    OOO      OOO   *
 *   SSS            III   MMM MMMMM MMM    OOO      OOO   *
 *   SSSSSSSSSS     III   MMM  MMM  MMM    OOO      OOO   *
 *   SSSSSSSSSSS    III   MMM   M   MMM    OOO      OOO   *
 *           SSS    III   MMM       MMM    OOO      OOO   *
 *           SSS    III   MMM       MMM    OOO      OOO   *
 *   SSSSSSSSSSS    III   MMM       MMM     OOOOOOOOOO    *
 *    SSSSSSSSS     III   MMM       MMM      OOOOOOOO     *
 *                                                        *
 *   SIMULATION OF COMPLEX MARINE OPERATIONS              *
 **********************************************************


 Enter system identification > sysa
 Enter initial condition identification > inib

 I-> SELECTION OF PROGRAM MODULE
 I
 I      INP  - SIMO INPMOD
 I      STA  - SIMO STAMOD
 I      DYN  - SIMO DYNMOD
 I      OUT  - SIMO OUTMOD
 I      PLO  - SIMO/RIFLEX PLOMOD
 I      S2X  - SIMO S2XMOD
 I
 I      PINP - Print postscript inpmod/stamod/outmod file (simo.plt)
 I      PPLO - Print postscript plomod file (pscr-meta.dat)
 I
 I      DEF  - Redefine default files (for default file names)
 I      LIS  - List identifiers (for default file name)
 I
 I      TERM - Terminate
 I
 Select option >

The user is first asked to specify the system identifier and initial condition identifier. They are described in previous sections, and are used to transfer default file names between the modules.

The user has the following options:

  • switch between the program modules

  • send print files to printer

  • change default file names

  • terminate SIMO program system

If for example the INPMOD module is selected, the system will respond with the following:

    ***************************************************
    *                                                 *
    *   III   N   N   PPPP    M   M    OOO    DDDD    *
    *    I    NN  N   P   P   MM MM   O   O   D   D   *
    *    I    N N N   PPPP    M M M   O   O   D   D   *
    *    I    N  NN   P       M   M   O   O   D   D   *
    *   III   N   N   P       M   M    OOO    DDDD    *
    *                                                 *
    *     Version      2      Release      2          *
    *                                                 *
    *     Module linked at 27-OCT-1994 11:02          *
    ***************************************************

    System identifier . . . . . . . : sysa
    Initial condition identifier. . : inib

 Use default file names ? (Y) :

The module name, version and release number and the link date/time, the system and initial condition identifiers appear on the screen. It is strongly recommended to use default file names.

    +-----------------------------------------------------------------------+
    ! File : pri-sysa.lis                                                   !
    ! has been opened as PRINT FILE                                         !
    +-----------------------------------------------------------------------+

    The module allows test print from maximum  10 routines

    Specify number of routines           (                0 ) :

        The following default plotting parameters are used:
        ---------------------------------------------------

        Screen device                 :   72
        Plotting device               :   90
        Plot file                     : simo.plt

    Use default values ? (Y)                                        :

The file name for printed output from the module is displayed. Error messages will be written on this file. There is an option for output of test print from the different program modules. It can be used for debugging purposes in cooperation and on instruction from program system aministrator, and normally the number of routines for test print should be set to 0 (default value).

All modules except DYNMOD generate plots. These can either be seen on screen or sent to postscript files. The default names are simo.plt or pscr-meta.dat (PLOMOD). These files can be opened in i.e. Ghostview and then copied directly into i.e. Microsoft Word.

The following plotting devices are available: