Restrictions and known problems for version 16.1: August, 2016

The following restrictions are known for the current release version 16.1:

  • The Windows un-installer does not support multiple versions (v15.1, v16.1) side by side. If you want to uninstall a previous version then do it first, before installing a newer version. If an installation is broken, consult the Installation section in the README file for manual installation tips.

  • One feature that is not treated well is the rolling direction parameter CHI. It is generally advised to use CHI=0 or 180 or restrict CHI to at most a few degrees.

  • The results may contain a significant discretisation error when a small number of elements (7 x 7, 15 x 15) is used. Particularly the frictional work appears to be susceptible to this.

Restrictions and known problems for version 15.1: October, 2015

The following problems exist in version 15.1 that are solved in version 16.1:

  • The plot programs for visualizing results in Matlab don't work well with newer Matlab versions (R2014b or newer).
  • When Fastsim is used for steady state rolling, the rolling step DQ must be equal to the grid size DX.

Restrictions and known problems for version 14.1: December, 2014

The following problems exist in version 14.1 that are solved in version 15.1:

  • Negative values for the approach aren't dealt with properly in Hertzian problems.

Restrictions and known problems for version 13.1: September, 2013

The following problems exist in version 13.1 that are solved in version 14.1:

  • The NormCG solver may fail in case the solution of the problem consists of an empty contact area.

  • The reading of numerical influence coefficients (C=3) is not fully robust.

Restrictions and known problems for version 12.2: June, 2012

The following problems exist in version 12.2 that are solved in version 13.1:

  • The CONTACT GUI stopped working after updating Java in April 2013. It worked ok with Java 7 update 15, but not with Java 7 update 22. The problem occurs also with Java 6 update 45. The resulting behavior is as follows: selecting an input-file works ok, but no output is obtained from Check Input or Run Experiment anymore:

    screen-shot of CONTACT GUI

    You may download a new version of the CONTACT GUI here. Store this file on your computer, and then use it to replace the original version in the bin-directory of the CONTACT installation.

  • Long runs with large grids may fail due to the amount of memory that is required. This is because some data that are used in the computations are held in memory for a long time. These are cleaned up when the program terminates. If you experience problems because of this ("forrtl: severe (41): insufficient virtual memory"), you may want to upgrade to version 13.1.

Restrictions and known problems for version 12.1: January, 2012

The following problems exist in version 12.1 that are solved in version 12.2:

  • The messages displayed by the CONTACT GUI can be confusing at first to new users. The CONTACT executable says that it's done: "If you want to continue, you must restart this program", then the Java GUI reports that the executable is done: "Execution terminated". No error is involved here.

    screen-shot of CONTACT GUI

  • There's a small bug in the guided input facility concerning Hertzian inputs. Currently you cannot use the guided input for selecting method IPOTCN=-1 (curvatures A1, B1).

Restrictions and known problems for version 11.1: April, 2011

The following problems exist in version 11.1 that are solved in version 12.1:

  • On Windows 7 (and probably Vista as well), write access is restricted for the directory Program Files (x86). You should move the examples directory to a different location before running the program.

  • The results of visco-elastic problems should be treated with care. The corresponding parts of CONTACT have not been validated for a long time. We particularly expect inaccuracies when using different materials for the two bodies.

Restrictions and known problems for version 10.2: October, 2010

The following problems exist in version 10.2 that are solved in version 11.1:

  • The file-name for .mat-files is restricted to 72 characters. This causes problems when using the CONTACT GUI, which uses full pathnames, when using the default long installation path.

  • When reading input for the subsurface stress calculation, some errors in the user input are not well detected. Particularly "end-of-file". If you provide less coordinate values than you said you would, the program seems to hang indefinitively. Also, better not use z-coordinate exactly 0, because this causes difficulties for the program as well.

Restrictions and known problems for version 10.1: January, 2010

The following problems exist in version 10.1 that are solved in version 10.2:

  • In non-quasiidentical problems, i.e. when using different material constants for the contacting bodies, there was a serious error in the interaction between normal and tangential parts. For instance the theoretical results for the Spence compression problem could not be reproduced with version v10.1. This error is corrected in the current release.

  • A problem existed with respect to the Carter2D example in the previous release. The ConvexGS solver did not always converge when run on a multi-core PC. This is resolved by using the SteadyGS solver instead. It may also be circumvented by disabling parallel computing on multi-core PC's, by setting the OMP_NUM_THREADS environment variable to 1.

  • In input option IBASE=3 (undeformed distance: "difference of two sines", the signs of b_3 and b_6 are changed. There was an inconsistency between the program and its User Guide.

  • Small restrictions with respect to the amount of input data for options IBASE=2 and E=2 have been removed.

For more information refer to the release notes of the corresponding release.