Answer:
The line thicknesses in RFEM and RSTAB can be changed in the display properties.
Use the pull-down menu "Options" → "Display Properties" → "Edit".
In the "Model Data" → "Members" or "Lines" tab, you can then define the line thickness of the individual member types and lines.
Note
If you have already made several changes this way, but do not want to use them all the time, you can save them in the configuration manager and work with these settings, if necessary.
To do this, select "Configuration Manager" → "New Configuration" → "Display Properties" and set the desired settings. You can work with these settings using the "Set Configuration as Current" function.
