25.1. General Product Limitations

This section describes limitations that can be present in the Mechanical application during certain conditions.

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General Limitations

Frequency Response Result

For harmonic-based analyses when you:

  1. Solve the analysis with the Multiple Steps property (Analysis Settings > Step Controls) set to No.

  2. Change the property setting to Yes and resolve.

  3. Insert and evaluate a Frequency Response result.

The application may display incorrect values in the Minimum Frequency and Maximum Frequency properties of the Options category of the Details pane for the result. For this case, the data included in the Graph and Tabular Data windows is correct.

3D Charts

3D charts, such as Waterfall Diagrams and rainflow charts, may not display any text in the chart as a result of machine configuration. Setting the Environment Variable ANS_OGL_3D_GRAPH_TEXT to 1 may address the issue. Be sure to close and restart all instances of Mechanical and/or Workbench once you define the environment variable.

Averaging Distributed Loads

Loads that are distributed evenly across geometric entities may use averaging that can cause the applied load value to deviate from the exact input value depending on mesh quality. For more accurate loading application, increase mesh quality in the region of application especially for curved surfaces or any time the mesh deviated from the idealized geometry.

Unsupported Characters in File Path

The application creates reference files that contain analysis information that is read back into the application during solution processing. Certain textual characters can create issues during this reading process. Avoid the use of the following unsupported characters in your file naming conventions and file path definition:

  • Quote character (“)

  • Ampersand (&)

  • Apostrophe (‘)

  • Greater than and less than characters (< >)

  • Japanese and Chinese characters

Numerous Objects in Outline

If your analysis includes an exceptionally large number of objects, the Outline content may appear incomplete. The application has a display limitation of 65,536 objects. If the number of objects exceeds this threshold, any additional objects are not displayed.

Tabular Data Results

For results displayed in Tabular Data window, if 0 (zero) displays for both the Minimum and Maximum values of a row, the result set may not contain result data. You can use the Retrieve This Result option (via right-click on table row), to view result sets in order to determine if any data exists for the set. If no data is available, the result contours in the Geometry window display as fully transparent.

Color Coding

Color coding may change or disappear when displaying shared topologies using both the By Connection edge coloring and the Section Plane features. The By Connection option displays connectivity color coding, while the Section Plane feature is used to cut or slice the model to view its interior.

Mechanical 14.0 or Previous on Linux

When you are running Mechanical version 14.0 or any previous version on a Linux system, you may experience graphical distortions when animating results, rotating an animation of results, as well as zooming in and/or out on your results.

Application Delays

When running a Mechanical session on the Linux operating system, if you encounter a delay while meshing or launching the Mechanical application or even a crash of the Workbench application, a potential solution is to create a new session with the Hardware Acceleration option turned off (display the OpenGL tab and deselect the Hardware Acceleration option).

Resuming Projects on Linux

If you are resuming a project in Mechanical on the Linux platform, there is a restriction that the path to the project, as well as the project name, include ASCII characters only, otherwise, the project will not open.

Nice DCV

When using Nice DCV to remotely connect to a Linux machine running Mechanical, you may encounter display issues when using the Report, Print Preview, or Image to File features. To correct this issue, it is necessary to turn off DCV in the Nice DCV control panel, close and reopen Mechanical, and then generate the Report, Print Preview, or Image to File. Once complete, close the application, turn DCV back on, and then reopen the application once again.

Nahimic Audio Driver

If you are running the Nahimic audio driver on your system, the Mechanical application could unexpectedly close when performing certain tasks, such as exporting an image of the Geometry window. Disabling the driver should address the issue. The Nahimic application is not provided by or related to any Ansys products.

Using 4K Displays with Mechanical

Currently, Mechanical does not support 4K displays. When Mechanical is initially launched on a 4K display, it appears to display normally. However, some panes (such as Scripting View, ACT Log, and ACT Wizards) will not display correctly. Content in these pages may be cut off or appear too small compared to the rest of the user interface.

To address these issues, do the following:

  1. On the Windows toolbar, select Start > Ansys 2024 R1.

  2. Right-click the Mechanical 2024 R1 icon and select More > Open file location from the context menu.

  3. In the Ansys 2024 R1 folder, right-click the Mechanical 2024 R1 icon and select Properties from the context menu.

  4. Switch to the Compatibility tab.

  5. Under Settings, click Change high DPI settings.

  6. Select the check box next to Override high DPI scaling behavior. Scaling performed by:

  7. Select System from the drop-down menu below the check box.

  8. To save the change and close the dialog box, click OK.

Linux Specific Limitations

  • If you are using the Real VNC sever to remotely access the Linux version of Mechanical, you might experience problems while using the application. This is because Real VNC does not provide an Open GL context, which is needed for several new and improved features of Mechanical. To fix this problem, use one of the following workarounds:

    • Launch Workbench and Mechanical within a VirtualGL context by using the vglrun command. For example:

      vglrun /ansys_inc/v241/Framework/bin/Linux64/runwb2

    • Set the following environment variable to enable Mechanical to use software-based rendering instead of an OpenGL context:

      QMLSCENE_DEVICE=softwarecontext

    • Use a different VNC server to remotely access Mechanical.

  • Make sure that the file system server hosting your working directories ($HOME, solver files, /tmp, etc.) associated with your analysis, has file locking support enabled.

  • The application does not support copying and pasting text between a Linux Mechanical session and a Linux-based application, such as Xterm.

  • When you are running Mechanical, DesignModeler, or the Meshing editor on the Linux platform, the following error message indicates that there is insufficient storage available to complete the current operation.

    RPCSS ServiceMain failed with 14 (0000000e)
    Not enough storage is available to complete this operation.

    This is likely a result of an entry in the "/etc/hosts file" that is over 500 characters long. If possible, shorten the alias lists of this entry to correct the issue.

  • In the Editable drop-down controls, after you mouse over an item in the list, press the "enter" key to select it, or directly type the value in the edit box and press the "enter" key.

  • The following features have been disabled on the Linux platform:

    • Body Views for Connections

    • View Ports for graphical display

  • There are a few Linux platform behavior limitations when working with the Customize dialog:

    • The label of the Tabs and the Close button does not display.

    • The prompt that a key combination you are defining has a conflict does not display.

    • The feature to create a new toolbar is not available.

  • Depending on your Linux machine configuration and setup, you could experience issues with certain graphics features that require off-screen rendering, for example, exporting images and animations at resolutions different than the current window resolution. Issues may include:

    • Incorrect graphical output, such as a black image, an image containing just the graphics window's background color, or no image at all.

    • System crashes.

    • X server deadlocking.

    These kinds of issues could stem from the Mesa software drivers available on the system, especially if the machine does not have a properly configured dedicated GPU or if the machine is accessed remotely without hardware accelerated graphics.

    Setting the environment variable ANS_WB_FORCE_EGL = 1 may resolve the issue.

  • If you are using CentOS 8.1 in combination with Nice DCV and menu arrows appear to display as a "1". You may be missing fonts for the docking pane buttons Menu, Auto Hide, Maximize, and Close and you are displaying locally (even with VNC and DCV), you will need to add the font path to your XWindows display server.

    Use the command xset +fp $INSTALL_DIR/aisol/CommonFiles/Fonts/linx64 on your XWindows display server so your XWindows server can find the font files.

  • For Linux Workbench running on RedHat/CentOS 8.1, if you experience a fatal error when exiting Mechanical, DesignModeler, or the Meshing Editor, set the environment variable MWDONT_XCLOSEDISPLAY=1.