#### Further Information

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• ### Is it also possible to create members when importing a DXF file into RFEM?

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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.

• ### In the cross-section library, I get an error message saying that the material is not assigned to a cross-section. What should I do?

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The error message shown in Figure 01 is displayed if no material has been defined for the cross-section.

In this case, it is necessary to assign the material to the cross-section. To select a material from the material library, open the library by clicking the "Import Material from Material Library" button and select the material (Figure 02).

The procedure is shown in the video.

• ### It is not possible to design a SHAPE‑THIN cross-section due to invalid symmetry. What is the cause and how can I fix it?

RF-/ALUMINUM checks the symmetry of general cross-sections and compares them with the SHAPE-THIN evaluation if activating the "Determine symmetry by module and compare with SHAPE‑THIN definition" check box (Figure 01).

If both methods provide different results, the corresponding error message appears (Figure 02).

Usually, there are small inaccuracies in the SHAPE‑THIN cross-section. Thus, the cross-section Sec‑1.du9 shown in Figure 03 is not absolutely symmetrical to the Z‑axis: The Z‑coordinates of Node 1 and Node 4 as well as Node 55 and Node 60 do not match in the second decimal place.

SHAPE‑THIN classifies the cross-section as asymmetrical, but RF‑/ALUMINUM as monosymmetric to the z‑axis, so the error message shown in Figure 02 appears.

The SHAPE‑THIN cross-section should be checked for symmetry. When modeling in SHAPE‑THIN, it is useful to only display one side of the cross-section and to create the other half by mirroring. This is also shown in the video.

• ### How can I set the font type and the font size of the values in the result diagram?

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You can adjust the font type and size of the values in a result diagram in the "Result Diagram Settings" dialog box. To open the dialog box, click the [Result Diagram Settings] button (Figure 01).

In the "Result Diagram Settings" dialog box, select the category to be adjusted under "Colors and Fonts" (Figure 02).

The [Edit Fonts] button opens the "Font" dialog box where you can make the desired settings (Figure 03).

• ### How does the calculation of the moments of inertia differ when the cross-section consists of several unconnected or connected partial cross-sections?

If the cross-section consists of several unconnected partial sections, the sum of the moments of inertia is calculated without the parallel axis theorem components. The cross-section shown in Figure 01 consists of two angle sections that are not connected to each other.

The individual angle sections have the following moments of inertia:

Iy,1,2 = 180.39 cm4 (referred to the centroidal axes y, z)

Iz,1,2 = 65.05 cm4 (referred to the centroidal axes y, z)

The moments of inertia of the entire cross-section result in:

Iy,1+2 = 2 ⋅ Iy,1,2 = 2 ⋅ 180.39 = 360.78 cm4 (referred to the centroidal axes y, z)

Iz,1+2 = 2 ⋅ Iz,1,2 = 2 ⋅ 65.05 = 130.11 cm4 (referred to the centroidal axes y, z)

If the cross-section consists of several connected partial sections, the sum of the moments of inertia is calculated with the parallel axis theorem components. The cross-section shown in Figure 02 consists of two connected angle sections.

The individual angle sections have the following cross-section properties:

A1,2 = 16.25 cm²

yS,0,1,2 = ±2.30 cm (referred to the zero point)

zS,0,1,2 = 3.07 cm (referred to the zero point)

Iy,1,2 = 180.39 cm4 (referred to the centroid axes y, z)

Iz,1,2 = 65.05 cm4 (referred to the centroid axes y, z)

The cross-section properties of the entire cross-section result in:

yS,0,1+2 = 0.00 cm (referred to the zero point)

zS,0,1+2 = 3.07 cm (referred to the zero point)

Iy,1+2 = 2 ⋅ Iy,1,2 + 2 ⋅ A1,2 ⋅ (zS,0,1,2 - zS,0,1+2

Iy,1+2 = 2 ⋅ 180.39 + 2 ⋅ 16.25 ⋅ (3.07 - 3.07)² = 360.78 cm4 (referred to the centroidal axes y, z)

Iz,1+2 = 2 ⋅ Iz,1,2 + 2 ⋅ A1,2 ⋅ (yS,0,1,2 - yS,0,1+2

Iz,1+2 = 2 ⋅ 65.05 + 2 ⋅ 16.25 ⋅ (2.30 - 0.00)² = 301.46 cm4 (referred to the centroidal axes y, z)

• ### How do I activate or run RF‑/STEEL Cold-Formed Sections?

RF-/STEEL Cold-Formed Sections is a module extension of RF‑/STEEL EC3. The only thing you need to do is to activate the design for cold-formed cross-sections in the detailed settings of RF‑/STEEL EC3 (Figure 01).

• ### I would like to design a cross-section in RF‑/STEEL Cold‑Formed Sections that is not contained in the cross-section library of RFEM/RSTAB. What should I do?

Common cold-formed cross-sections can be modeled in SHAPE‑THIN. In General Data, select the "c/t parts and effective cross-section properties" check box (Figure 01).

Then, select the "EN 1993‑1‑3 (Cold formed cross-section)" option in the "c/t-Parts and Effective Cross-Section" tab of the Calculation Parameters dialog box (Figure 02).

You can optionally check the geometric conditions for the applicability of the standard specified in EN 1993‑1‑3 [1], 5.2. To do this, select the corresponding check boxes. If the geometric conditions are not met, an error message appears before the calculation.

First, enter the elements of the cross-section. The notional flat widths are usually generated automatically from the geometry conditions, but can also be created as user-defined in Table "1.7 Notional Flat Widths | EN 1993‑1‑3" (Figure 03) or in the corresponding dialog box.

Then, you can define stiffeners in Table "1.8 Stiffeners" or in the corresponding dialog box (Figure 04).

Furthermore, you should specify the buckling panel in Table "1.9 Buckling panels" (Figure 05) or in the dialog box. To do this, select the elements of the buckling panel. The stiffeners located in the stiffened panel are identified automatically.

For the design of a cold-formed cross-section in RF‑/STEEL Cold‑Formed Sections, it is sufficient to define the stiffeners and panels of the cross-section. It is not necessary to additionally calculate the effective cross-section in SHAPE‑THIN. Thus, you can start the calculation and click "OK" to confirm the warning message (Figure 06).

After saving the calculated cross-section, it can be imported into RFEM or RSTAB.

• ### How can I move a member or a line by using Drag & Drop?

The drag & drop function is very helpful for fast work in RFEM and RSTAB. It is first necessary to activate this option in the shortcut menu (Figure 01).

If you click a member or a line near the start or end node in the work window, you can quickly define the new connection point graphically.

However, if you grab a member or a line in the middle third, you can simply move the element to a new position.

If you additionally press the "Ctrl" key, the marked elements are copied.

The video first shows how to move the column head of Member 2 from Node 2 to Node 4. Then, it shows how Member 2 is moved to a new position.

• ### How can I display the color scale of a graphic in the printout report?

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When printing a graphic in the printout report, you can select the position of the color scale in the "Color Scale" tab. Furthermore, you can adjust the size of the color scale in the same dialog box. If deactivating the "No Color Scale" check box (Figure 01), this is displayed in the graphic in the printout report.

If a graphic has already been inserted into the printout report without a color scale, it is possible to display the color scale retroactively. To do this, right-click the picture. Then, select the properties in the shortcut menu (Figure 02) to open the "Color Scale" tab. You can also edit the position and the size of the color scale here.

• ### How can I insert a smooth range /a smooth line in the result diagram?

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In the Result Diagrams dialog box, it is possible to create smooth regions to prepare the results for engineering. This function is available when clicking the "Edit Smooth Ranges" button. A dialog box shown in Figure 01 appears.

Define the smooth ranges in the table columns on the left; the entries for Start, End, and Length are interdependent. Each region can be activated separately. The "Use for Results" section controls for which deformations, internal forces, stresses, or strains should be performed the smoothing. The smoothing can be Constant or Linear for all smooth ranges.

Furthermore, you can display a smooth line over the entire result diagram by clicking the button of the same name (Figure 02).

The integral of the smooth region is displayed if you select the "With result interpretations" option is selected in the result diagram settings (Figure 03).

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#### 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.

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