Appendix C: Analysis settings

1. Work array size in STAMOD, DYNMOD and OUTMOD

The size of the work arrays may be specified using the environment variables RIFLEX_STAMOD_MEM, RIFLEX_DYNMOD_MEM and RIFLEX_OUTMOD_MEM. The variables give the size in million Bytes, i.e. 4 times the number of million integer words. The minimum size is 4 and the maximum size is 800. From RIFLEX 3.6.17 / 3.7.25 the maximum size is increased to 1600. The value used is echoed on the .res file.

The default size of the STAMOD work array is 4 million integer words. This corresponds to specifying 16.

The default size of the DYNMOD work array is 8 million integer words. This corresponds to specifying 32.

The work array in OUTMOD may be specified in RIFLEX versions 3.4.7 and higher. The default size of the OUTMOD work array is 8 million integer words. This corresponds to specifying 32.

The procedure for setting environmental variables is described in Section 4 and Setting Environment variables on Linux.

The RIFLEX for Windows utility should be restarted after setting the environment variables.

2. Maximum number of arrays on the ifnsta and ifnirr files

The maximum number of arrays on the ifnsta and ifnirr files may be specified using the environment variables RIFLEX_MAXSTA_IFNSTA and RIFLEX_MAXIRR_IFNIRR. The values used are echoed on the _stamod.res or _dynmod.res file.

The minimum size of RIFLEX_MAXSTA_IFNSTA is 2000 and the maximum is 2000000. The default is 20000.

The minimum size of RIFLEX_MAXIRR_IFNIRR is 100 and the maximum is 100000. The default is 2000.

The procedure for setting environmental variables is described in Section 4 and Setting Environment variables on Linux.

The RIFLEX for Windows utility should be restarted after setting the environment variables.

3. Transforming time series on file ifndyn

After completing the time domain simulation, DYNMOD reads stored displacements, forces and curvature back from the ifndyn file and extracts times series which are then stored on the ifndyn file for subsequent use by OUTMOD. This will cause a lot of file IO if storage is specified for many response quantities at many time steps and may be very time consuming.

Depending on the available space in the DYNMOD work array, DYNMOD may not be able to transform the time series for all stored nodes / elements at the same time. Check the dynmod.res file for information about the time series transformation, e.g. for a very small test case:

Transforming displacements to time series in
1 groups of 50 nodes/elements each
took 0.06 s (wall clock time)

If the transformation is split in many groups, increasing the size of the DYNMOD work array may help (ref FAQ Section 1).

The amount of data transformed may be reduced by not storing response for nodes / elements that are not needed for post-processing in OUTMOD; e.g. for presentation of times series, response statistics, fatigue damage, distance time series. Note that one can obtain minima, maxima, mean, standard deviation and estimated period on the dynmod.mpf file even if the response quantities are not stored.

If the transformation remains unacceptably time consuming, a solution may be to run the simulation twice. The initial simulation may either be a shorter simulation with full storage or a long simulation without storage. The response quantities of interest may then be selected from the time series or from the key response on the mpf file and the simulation rerun storing only the selected response.

4. Setting environment variables on Windows

Environmental variables may be used to specify work array size or the maximum number of arrays on files, see Section 1 and Section 2. If not set, default values will be used by RIFLEX. For example to increase the DYNMOD work array to twice the default size, set RIFLEX_DYNMOD_MEM to 64.

On Windows 7:

  1. Click on Start at the lower left corner of the screen

  2. Right mouse click on Computer in the right hand column

  3. Choose Properties at the bottom of the menu that pops up

  4. Choose Advanced System Settings at the bottom left of the System window

  5. Choose Environment Variables at bottom right

  6. Set the desired variables

  7. Choose OK to save the settings

  8. Restart any command line window in order to update your environment

5. Running Linux scripts on Windows

The CYGWIN package (http://www.cygwin.com/) will enable you to run Linux-style shell scripts on your Windows machine.