Frequently Asked Questions (FAQ)

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Knowledge Base

Knowledge Base

In the Knowledge Base, you’ll find technical articles and tips & tricks that may help you with your design using Dlubal Software.


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  • Answer

    To determine the minimum reinforcement from restraint (drain of hydration heat) in RF-CONCRETE, you have to select at least one load case or CO for design in the "Serviceability Limit State" register of the 1.1 General Data input form. The analytical method of check for the serviceability limit state is activated by default in this tab. See Figure 01.
    After activating the checks in the serviceability limit state, you can now adjust their settings in input form 1.3 Surfaces. Switch to the Limit of Crack Widths tab in input form 1.3. On the right side, you'll find the "Minimum Reinforcement for Effects Due to Restraint". Once the box "Crack formation in the first 28 days" has been selected, the factor for controlling fct,eff,As,min can be entered. See Figure 02.
  • How do I change the default settings for the units so they are preset in every new file?



    The default settings are loaded for every new file. If you wish to change them, you have to create a new profile after making the desired changes and set it as "Default" (see figure). If you now start a new file, this setting remains saved. It is also possible to create several profiles, which can subsequently be loaded and managed.

  • Answer

    When a beam with variable cross-section dimensions is divided retroactively, the dimensions for the beam start and beam end can no longer be modified easily. Due to the resulting intermediate nodes, a new cross-section would have to be calculated for every member segment. In order for you to not have to do this manually, it is recommended to delete the members. In doing so, take care to only delete the selected members and not their nodes. The new member can subsequently be modelled from beam start to beam end and connected to the intermediate nodes with the "Connect Members" tool.

    Summary (see Figure 1):

    1. Delete members (nodes must remain unchanged)
    2. Insert new member from beam start to beam end
    3. Connect member with intermediate nodes

    In RSTAB, the members always have to be connected to each other in a node.

    This is not absolutely necessary in RFEM, because it allows a node to lie on a line without dividing the member (see Figure 2). It is therefore sufficient to modify the cross-section at the beam start and beam end. If the intermediate nodes (which members already connect to) already exist and you wish to create the tapered member retroactively in RFEM, it is recommended to deactivate the option "Auto Connect Lines/Members" (see Figure 3). Afterwards the member can be created without divisions at the intermediate nodes.
  • Answer

    If the "Authorization" dialog box (see Figure 1) is not displayed when starting the program, an authorization file has been already imported. In this case, please select in the Help → Authorization menu Diagnostics (see Figure 2). Save the text file and open it. Open the path in the Windows Explorer which is shown at "PermDataDirectory" (see Figure 3). In this directory, you find the file AUTHORE.INI which needs to be deleted. When starting the program the next time, the authorization dialog box, as shown in Figure 1, will be displayed. To activate the license, select the "Use full version" option (internet connection required).

  • How can installations be distributed via the network?

    FAQ 002317 EN Installation RFEM RSTAB SHAPE-THIN CRANEWAY RX‑TIMBER Glued‑Laminated Beam


    The installation packages can be distributed with a MSI file (Windows Installer Package). It is necessary to extract the MSI file from the installation package.

    You have to start setup.exe with the parameter "-E" (see Figure 1). For the example shown in the figure, the RFEM installation file has been copied to drive C:\. After the decompression, you find a new folder in the same path with the name "Dlubal_Program_Version Number_Architecture". For the example in Figure 1, a folder with the name Dlubal_RFEM_5.07.13.124218_64-bit has been created.

    The installation can be started afterwards from this folder with the command "msiexec -i .msi" (see Figure 2). If the authorization file should be imported at the same time and if the language should be German, the command is as follows:

    msiexec -i "Dlubal RSTAB 64-bit.msi" -passive -q TRANSFORMS=1031.mst AUTHORIZATION_FILE_PATH=\\[IHR SERVER]\AUTHOR.INI

    If the command -q (=-quiet) is used, the installation is carried out without graphical user interface.

    It should be ensured that the command prompt is started by right-clicking → Run as Administrator.

    If the program language should be English, the parameter "TRANSFORMS=1031.mst" has to be deleted.

    You can find detailed information about all commands and language IDs in attached "Software Deployment" document (see below).
  • How can I consider the second-order analysis for seismic design?

    FAQ 002316 EN Support & Training RF-DYNAM Pro - Natural Vibrations DYNAM Pro - Natural Vibrations RF-DYNAM Pro - Forced Vibrations DYNAM Pro - Forced Vibrations RF-DYNAM Pro - Equivalent Loads DYNAM Pro - Equivalent Loads


    In RF‑DYNAM Pro ‑ Natural Vibrations, it is possible to import the geometrical stiffness matrix. You can use it to consider the second‑order analysis.

    Find detailed information and an example in the attached PDF.

    Second-order analysis.pdf (471 kB)
  • Answer

    First, open the result diagram of a member, line support, section or line. Then select the desired internal forces and deformations.
    Finally, right-click the navigator and select Save Check Boxes State.
    Use Refresh Check Boxes State (this button is now available) to cancel your settings.

  • Answer

    The IFC interface is structured in different areas, the so-called Views. The export from RSTAB/RFEM is performed in StructuralAnalysisView. At the same time, it is possible to transfer the structural model with member elements, concentrated line and member loads, supports as well as support conditions, load cases, etc. Importing an IFC file generated from RSTAB/RFEM is only possible in the third-party software if it also supports StructuralAnalysisView.

  • Answer

    This problem cannot be generally solved without further background knowledge. Therefore please contact our support at and send us the following information:

    • We need the diagnostics file (authorization.txt). You will receive it if you follow the instructions shown in figure 2. Just run the program in demo mode.
    • Please specify which program you are running (RFEM, RSTAB, RX-TIMBER, etc.).
    • If you are trying to access a network dongle, please inform us if the computer you are using is located on the same network as the licence server, or if a VPN connection is used to communicate with the server.
  • Answer

    If you prepare comments, they are saved in the current configuration. You can save this configuration and then import it to another computer.

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