#### Further Information

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• ### Where can I find the details for the layer structure in the RF-GLASS add-on module?

The detailed settings can be made separately for each layer composition. You can open it by using the "Edit Details for Layer Composition ..." button.

The detailed settings differ depending on whether the calculation type has been set to "Local" or "Global" in the General Data.

• ### Is it possible to export the results from RF-CONCRETE Surfaces to Excel? For example, I would need the steel stress in the SLS.

Yes, the results can be partially exported. The export function is available for the result tables in the module (as of window 2.1).

Using the example of the steel stress in the SLS, it would be possible, for example, to perform only the steel stress analysis and then export the table in Window 3.3.

When displaying the table in Window 3.3, you can choose between FE mesh points and grid points. The grid can be adjusted as a property of the surface.
• ### I have entered the cross-sections U180 and a flat steel 30 x 300. Unfortunately, I cannot connect the cross-sections with each other; no connected cross-section is calculated.

With the "Connect Node and Element" function, you can connect unconnected cross-section parts that are at a certain distance from an element. The connection is made using an element with a thickness of zero. To access this function, select the menu "Edit" → "Connect Node and Element".
• ### How can I open and close RSTAB/RFEM in the background via the COM interface?

By initializing a variable of the Application (Interface) type with "new", RFEM/RSTAB is started in the background. Use this variable to create a new model using the CreateModel method or to close the program with the Close command

In the following, an example of where RSTAB is started, the program creates a model with a node and ends the program again:

Sub RSTAB_open_close ()Dim filename As Stringfilename = Application.ActiveSheet.Cells (7, 3)'start rfemDim iApp As RSTAB8.ApplicationSet iApp = New RSTAB8.ApplicationiApp.LockLicenseiApp.ShowOn Error GoTo E'create modelDim iMod As RSTAB8.IModel2Set iMod = iApp.CreateModel (filename)    'add data to modelDim nd As RSTAB8.Nodend.no = 10nd.X = 1nd.Y = 2nd.Z = 3    Dim iModdata As RSTAB8.iModelDataSet iModdata = iMod.GetModelData    iModdata.PrepareModificationiModdata.SetNode ndiModdata.FinishModification    iMod.Save filenameE: If Err.Number <> 0 Then MsgBox Err.description,, Err.Source    Set iModdata = NothingSet iMod = Nothing    iApp.UnlockLicenseiApp.CloseSet iApp = Nothing    End Sub

The iApp.Show command is optional. This ensures that the program is not displayed in the background, but is displayed normally.

In the Downloads, you can find an EXCEL macro with subroutines for RFEM and RSTAB.

Please note that the folder where the file is created must exist.

• ### I use the automatic combinatorics, but some load cases are not used in the created combinations. How can I change it?

If the automatic combinatorics has been activated in the General Data, actions, combination rules, action combinations, and load or result combinations are created automatically. In this case, some default settings have been selected by the program developers, which apply in most cases.

By default, the following design situations with the respective combination rules are created:

• ULS: Ultimate limit state for permanent or temporary situation
• SLS: Serviceability limit state for characteristic situation
• SLS: Serviceability limit state for common situation
• SLS: Limit state of serviceability for quasi-permanent situation

If load cases of the type "Exceptional" or "Earthquake" have been defined, they are not considered in the preset combinations. For these load cases, a new combination rule must be created manually. The appropriate design situation can be selected in the list.

Unusual load cases are only used in the "Ultimate Limit State - Unusual" or "Earthquake" rules.

• ### How can I consider the flexibility of adjacent objects that have no line release?

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Already in this FAQ, the problem is explained that when more than two objects to be released, the great function of the line release can be problematic.

For an adjacent member, there is a fairly simple solution. The node of the member or line adjacent to the line release is simply placed in the line release.

Figure 1 and the video show this step.
• ### Is it possible to adjust the initial values of the temperature courses entered for the fire resistance design? For example, I would like to adjust the initial value of the moisture content.

The fire resistance design is based on the temperature course from Annex A EN 1992‑1‑2.

The initial values for temperature courses cannot be adjusted in the add-on modules (RF‑/CONCRETE Members and RF‑/CONCRETE Columns). The temperature curves according to Annex A EN 1992‑1‑2 are based on the following assumptions:

• The specific heat of concrete corresponds to the specifications according to EN 1992‑1‑2, 3.2.2.
• The moisture is 1.5%. For moistures greater than 1.5%, the specified temperatures are on the safe side.
• The thermal conductivity of concrete is the lower limit value mentioned in EN 1992‑1‑2, 3.3.3.
• The emissivity value of the concrete surface is 0.7.
• The convective heat-transmission coefficient is 25 W/m²K.
• ### Why is a trapezoidal and no triangular load displayed for a surface load with a linear load distribution (from 0 to 50 kN/m²)?

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It is due to the relative limit settings that can be defined for each load type in the display settings. In order to display the load in a triangular shape, it is necessary to reduce the minimum value for "1 [kN/m²]". The smallest value that can be set is 0.1%.

The relative limit settings are used to control the minimum and the maximum display size in relation to the maximum dimensions of the entire model.
• ### I perform fire resistance design in RF‑/CONCRETE Columns. Which source does the design formula according to Section 5.8.8 refer to?

The fire resistance design with RF-/CONCRETE Columns is performed according to the simplified calculation method according to EN 1992-1-2 [1] , Section 4.2. The program uses the zone method described in Annex B.2:

The reduction of the load-bearing capacity in case of fire is represented by a reduction of the cross-section of the component and a reduction of the material strengths. The concrete zones that are directly exposed to fire and thus damaged are not taken into account for the equivalent cross-section used for the fire resistance design. The fire protection design is performed with the reduced cross-section and the reduced material properties analogous to the ultimate limit state design at normal temperature.

That is: The nominal curvature method according to [1] , paragraph 5.8.8 is performed with the hot materials and reduced cross-section.

• ### How can I transfer the shear at the interface between concrete cast at different times to a printout report?

In the printout report selection, you can add the intermediate results of the add-on module in the Reinforcement tab.

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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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