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Frequently Asked Questions (FAQ)
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No, this is not possible in RF-CONCRETE Surfaces (in the current state of development).
If you have activated a basic reinforcement and/or the serviceability limit state design in RF-CONCRETE Surfaces, there are several options available in the Results navigator for the graphical display of the "provided reinforcement".
However, no rendering of the rebars or mesh reinforcement is generated here. Rather, it is a color representation of the result values in [cm²/m] for the longitudinal reinforcement or in [cm²/m²] for the shear reinforcement.
AnswerThe load application in RF-/FOUNDATION Pro is - regardless of the foundation type - always on the foundation top edge.
Yes, minimum moments are also considered when punching through foundation plates. See also FAQ004371 (link below).
In the current state of development (as of July 2020), however, the favorable soil pressure within the critical perimeter is not taken into account when determining VEd .
Regarding the analytical calculation of SLS, you should note that the calculation is based on a provided or applied reinforcement for SLS.
The provided reinforcement can result, for example, from the ultimate limit state design, the defined basic reinforcement, or the automatically determined required reinforcement for SLS. The reinforcement applied to the SLS design can be displayed graphically.
If there are too small or no reinforcement results from ULS or the basic reinforcement in some areas and no required reinforcement is determined for SLS at the same time, the serviceability limit state design is performed without or with too small reinforcement. In this context, very high results may occur during the deformation, for example. Also, there may be poor convergence.
It is necessary to ensure that there is a reinforcement in each area of the structural system. For this, you can apply a basic reinforcement or a minimum reinforcement, for example.
I am trying to verify RF‑CONCRETE Surfaces on the basis of the results of the example from the manual. Chapter 2.4.3 describes the determination of the statically required reinforcement. Unfortunately, I cannot create an example that exactly represents these results. Can you send me the corresponding example?
You can download the corresponding example under the link below.
The results shown in Figure 2.39 in the manual of RF‑CONCRETE Surfaces come from the reinforcement in the bottom position in Grid Point R27 - see the following figure with the design details for this point.
It is possible to use the "isolines" instead of displaying the results with "isobands" in the graphic.
First, switch to the "Isolines" display.
Then, you can additionally set in the Display navigator that the "Result Values Defined Automatically" should be displayed for the isolines.
Yes, it is possible, for example, if a file (calculated in version 5.23.01) is opened in an older version (such as 5.20.01).
The add-on modules for reinforced concrete structures have no backward compatibility. This means that the module entries must be deleted, depending on the version change.
For instance, this may be necessary if there is a function or a feature contained in the latest program version, which was not yet available in the older version. To avoid compatibility problems, the entries in the add-on modules are removed.
In the example, the file from version 5.23.01 is opened in version 5.20.01. In this case, the entries from RF‑CONCRETE Surfaces will be lost. If you open it in the version 5.17.01, for example, the entries from RF‑CONCRETE Members is also lost.
To avoid the problem, it is recommended to conclude a service contract and use the current version of RFEM.
AnswerYes, the results can be partially exported. The export function is available for the result tables in the add-on module (as of Window 2.1).Using the example of the steel stress in SLS, it would be possible to only perform the steel stress analysis and then export the table in Window 3.3, for example.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.
AnswerThe 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.
AnswerThe fire resistance design with RF‑/CONCRETE Columns is performed according to the simplified calculation method according to EN 1992‑1‑2 , Section 4.2. The program uses the zone method described in Annex B.2:In case of exposure to fire, the bearing capacity is reduced due to a reduction of the component's cross-section and a decrease of 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 , Section 5.8.8, is performed with the hot materials and reduced cross-section.
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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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