Issues and Limitations

Table of contents

• Current Limitations
  • Ansys Workbench Analysis Types
  • Future Analysis
  • Shared Memory Parallel (SMP)
  • Shared Web Licensing
• Known Issues
  • HPC license selection broken in 2022 R2 and 2023 R1
  • TAR not installed
    • Workaround - Install TAR manually
  • Rescale License Monitoring Fails
  • Certificate Verification Failed

Current Limitations

Ansys Workbench Analysis Types

CloudConnect supports the following Ansys Workbench analysis types:

• Eigenvalue Buckling
• Harmonic Acoustics
• Harmonic Response
• Modal
• Modal Acoustics
• Random Vibration
• Response Spectrum
• Static Acoustics
• Static Structural
• Steady-State Thermal
• Thermal Electric
• Transient Structural
• Transient Thermal

Future Analysis

To solve pre-stressed or linked analyses using CloudConnect, each analysis needs to solved individually and results read back into Mechanical after each step. For example doing pre-stressed Eigenvalue Buckling analysis you would have to perform these steps:

1. Create a Static Structural analysis
2. Create an Eigenvalue Buckling analysis
3. Set Static Structural as pre-stress for Eigenvalue Buckling
4. Start the Static Structural job
5. Download and read Static Structural results into Mechanical
6. Start the Eigenvalue Buckling job
7. Download and read Eigenvalue Buckling results into Mechanical

If the Future Analysis is set in the Mechanical Analysis Settings, CloudConnect will automatically add any additional files to result_archive.tar.gz. Current support for Future Analysis is listed in the table below.

Supported Future Analysis Types

Future Analysis	Example Project	Additional Files
Prestressed analysis	Static Structural → Eigenvalue Buckling Static Structural → Modal	fileN(NN).rMMM file.rdb file.ldhi
MSUP Analyses	Modal → Harmonic Response Static Structural → Modal → Harmonic Response	fileN(NN).mode fileN(NN).lmode fileN(NN).emat fileN(NN).esav fileN(NN).full

Shared Memory Parallel (SMP)

CloudConnect doesn’t currently support Shared Memory Parallel mode in Ansys Mechanical. This means that CloudConnect is unable create new jobs using the SMP solver flag or use analyses solved with Shared Memory Parallel as a pre-stress environment for future analyses.

Shared Web Licensing

Ansys Shared Web Licensing is only supported for Ansys 2023 R2 and newer.

Known Issues

HPC license selection broken in 2022 R2 and 2023 R1

There is a known issue when solving with Ansys Mechanical 2022 R2 and 2023 R1, which causes the solver to not honor the HPC license increment selection by the command line flag -ppf. HPC license selection is confirmed to be working correctly with Ansys Mechanical 2023 R2.

TAR not installed

CloudConnect uses TAR for handling input and output archives. TAR is included in Windows 10 (1803) from build 17063. CloudConnect falls back to a Python implementation if TAR is not available. This slows down the archive handling by a factor of 5x.

Workaround - Install TAR manually

TAR can be installed manually on older Windows versions. If TAR is found in the in Windows PATH, CloudConnect will be able to use it. You can test it by opening the Windows Command Prompt (cmd.exe) and calling tar --help.

Rescale License Monitoring Fails

CloudConnect checks the status of Ansys licenses at Rescale when drafting or starting a job with Floating license type selected. If status check is successful and enough licenses for the job are available, the job will start immediately in the Rescale.

If enough licenses are issued but are currently not available, the job will be queued on Rescale until enough licenses are returned from on-premise or Rescale runs.

If not enough licenses are issued or license status check fails, CloudConnect raises a warning and let’s the user to decide how to proceed.

License checking typically fails if the license proxy or the on-prem license server is down or they are not configured correctly. Typical misconfiguration error is related to license proxy hostname setting and the fix is explained in the Admin section of this page.

Certificate Verification Failed

On some systems connecting Rescale using CloudConnect may fail due to out of date SSL certificates. In such cases CloudConnect will fallback to using a certificates bundled with the installation, but in some cases even this will fail with an error similar to

ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate has expired (_ssl.c:997)

in the debug log. This can be mitigated by using a CloudConnect version newer than 232.12 with Ansys version newer than 23 R1. With this combination of CloudConnect and Ansys, the system trust store certificates are used instead.