# Frequently Asked Questions (FAQ)

#### Customer Support 24/7

In addition to our technical support (e.g. via chat), you’ll find resources on our website that may help you with your design using Dlubal Software.

Receive information including news, useful tips, scheduled events, special offers, and vouchers on a regular basis.

• ### Can I use a SHAPE-THIN 9 cross-section in older versions of RFEM or RSTAB?

Yes, it is.
The cross-section created in SHAPE‑THIN 9 (file extension *.du9) should be opened and saved as SHAPE‑THIN 8 cross-section (file extension *.du8) in SHAPE‑THIN 8.

To open the cross-section in SHAPE-THIN 8, set the file type to "All Files".

Now you can save the cross-section as SHAPE-THIN 8 as usual and import it in earlier program versions.

• ### After importing loads from another model, Warning No. 11003 appears. Some free loads are obviously perpendicular to the projection plane. What can I do?

New

004461

The projection plane and the load direction are different parameters and independent of each other.

While the load direction is the actual direction of the acting load, the projection plane together with the corresponding coordinates of the load position describes the plane from which the position of the load is projected onto the surfaces subjected to the load.

In the example file, a surface perpendicular to the load was selected incorrectly for the free load. Thus, the warning appears during the calculation.

In the case of free loads, it is therefore always necessary to ensure that all surfaces rest in the correct projection plane.
• ### Is it also possible to create members when importing a DXF file into RFEM?

New

004425

The lines in a .dxf file can be imported as lines or members. You can select the "Create Members" option in the "ASCII Format DXF (*.dxf)" tab of the import dialog box (Figure 01).

When importing members, the names of layers are transferred as cross-section names, and the first predefined material is assigned. If a cross-section of the Dlubal cross-section library and a material from the Dlubal material library are recognized from the layer name, they are transferred. The layer name must be specified in the format [Cross-Section Name]$[Material Name] (for example, IPE 300$Structural Steel S 235 JR).

The import of lines/members is shown in the video.

• ### When trying to import a model from AutoCAD into RFEM, I am getting the error message "3DSOLID or REGION entity detected. Those entities are written in binary format, so import is not possible."What does this mean?

The reason this warning appears is because it is not possible to import 3D solids into RFEM from AutoCAD. Only 1D and 2D members can be imported in from AutoCAD to RFEM. The reason for this is because only line elements can be imported so with 3D solids they could not be automatically generated.

• ### When importing a .stp (DSTV) file that I have exported to RFEM/RSTAB, I get an error message shown in the figure. No cross-sections are exported. Why?

004367

In order to carry out the import in RFEM/RSTAB by using the DSTV interface, the program requires the nodes where the cross-sections can be located.

It often happens, that members are only selected in the case of the "Export only selected objects" option (Figure 02). In this case, the nodes are missing in the selection. The model cannot be created.

Therefore, you have to select all objects that are necessary for the description of the model by using the "Select" → "Related Objects" option (Figure 03). Then, the import is carried out properly.
• ### When opening an RSTAB 8 file including scissor hinges in RFEM 5, I get an error message saying that the scissor hinges cannot be imported correctly. Why?

004320

Please check the definition of the scissor hinges in the RSTAB 8 file.

To properly consider the function of a scissor hinge, the scissor hinge of the same type must be specified on the member ends of both members "touching" at a node. If this is not the case, you get the mentioned error message.

If you have got this error message displayed when opening an RSTAB 8 file in RFEM 5, this may lead to problems in the calculation, for example, the structure becomes unstable due to the incorrect hinge definition (already in RSTAB 8).

Therefore, the problem should be adjusted either already in the RSTAB 8 file or in the RFEM model after the import.

• ### How can I import a parameterized cross-section table into the cross-section library?

004290

The cross-section library in RFEM or RSTAB provides the option to import a list of parameterized cross-sections into a user-defined cross-section library by using the "Import Cross-Section Table from File" function.

For this, the cross-section shape to be imported must be compatible with the shape that can already be parameterized in the Dlubal cross-section library (also known as a cross-section table). This cross-section shape then determines the type and order of the import parameters.

To import a user-defined cross-section table, proceed as follows:

1. In the Dlubal cross-section library, find the cross-section table that is compatible with the cross-section table that you want to import.

Here, the parameterizable cross-section types (thin-walled, massive, and timber) specify the necessary parameters in the correct order for the import directly in your input dialog boxes by using the input boxes from top to bottom.

For the rolled cross-section types, you can find the required parameters in the correct order by using the "Parametric Input" function.

2. Create a CSV table for the cross-section table to be imported, which describes a unique cross-section by using the parameters "Name" + shape parameters in each line, based on the previously defined parameter list and order.

The shape parameters must be specified in mm.

For the data representation reasons, the individual cross-section names in the CSV file should start with the same text fragment as the CSV file name itself. This ensures that the new cross-section table in RFEM or RSTAB have the name of the CSV file.

3. Import the CSV file with the used cross-section table into the user-defined cross-section library.

4. Use the cross-sections of the newly imported cross-section table in your models.

• ### Which features are available for the data exchange between Grasshopper and RFEM?

004260

After the successful installation of the interface, the RFEM5 toolbar is available. The corresponding components allow you to control the export to RFEM. To do this, simply drag and drop them into the programming interface. The import from RFEM is not possible.

The "RFEM 5 COM Component" allows for communication between Grasshopper and RFEM. As soon as you use this component with the geometrical information, the export will begin. An opened RFEM file is expected. It is recommended to use an empty file because the export overwrites all information. The update mechanism is not implemented at the moment. By using "Value List," you can additionally define the unit which is used to describe the geometry. The modifications of tolerances are usually only necessary if the points have been defined very close to each other. You can enter the number to be stored for this in "Panel."
The "RFEM 5 Member Component" allows you to attach additional information to the geometry (lines, curves). These are considered during the export to RFEM so that the members can be created. The material and cross-section name can be entered in a text box (panel). The member rotation can be defined in [rad] by using "Number Slider." For the definition of member hinges, it is necessary to additionally load the "RFEM 5 Member Hinge Component." The input consists of 6 degrees of freedom which can be controlled individually. For the release of a degree of freedom, it is necessary to define the value "0," and spring constants are expected in the units [N/m] or [Nm/rad]. It is not possible to change the unit. Currently, nonlinearities cannot be specified.
The "RFEM 5 Surface Component" can be used in a similar way as the "Member" component. A surface is expected when entering the geometry. The material can be attached to them by using the "panel." The surface thickness can be defined in [m] by using the number slider. The stiffness type of the surface can be controlled by "Value List" with the predefined types.
You can create nodal supports by using the "RFEM 5 Nodal Support Component." On the Input page, you can define the points to be supported. In this case, it is recommended to use the already existing definition nodes of surfaces or lines. All 6 degrees of freedom can be controlled. In this case, the value "0" means a release in the respective direction, "-1" means a fixed support. Spring constants can be defined in the same way as member hinges.

You can download the Grasshopper file shown in the figure. It is only necessary to activate the "RFEM 5 COM Component."

• ### Which features are available for the data exchange between Rhino and RFEM?

004255

In principle, it is very simple to use the interface. After the successful installation, the Dlubal toolbar is available in Rhino. This includes two icons (Export and Import).

"Import" allows you to import data from RFEM to Rhino. In this case, the whole RFEM model is always imported. No update is necessary. The data is added to the existing structure.
"Export" allows you to export data from Rhino to RFEM. The entire structure is usually exported. If you only want to export parts of the structure, select them before starting the export. In order to perform the export, it is necessary to open RFEM and create a file. Please note that the export procedure overwrites all existing data of the opened file. Therefore, it is recommended to open an empty file.

• ### Why are the line loads generated via "Tools → Import Support Reactions as Load" not distributed polygonally?

004235

When importing support reactions as loads from another RFEM file, it is possible to select the type of load distribution. In this case, the "Uniform" and "Polygonal" options are available.

1 - 10 of 64

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

#### First Steps

We provide hints and tips to help you get started with the main programs RFEM and RSTAB.

#### Wind Simulation & Wind Load Generation

With the stand-alone program RWIND Simulation, wind flows around simple or complex structures can be simulated by means of a digital wind tunnel.

The generated wind loads acting on these objects can be imported to RFEM or RSTAB.

#### Your support is by far the best

“Thank you for the valuable information.

I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. I have used a lot of software with a support contract in the field of structural analysis, but your support is by far the best. ”