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.
Frequently Asked Questions (FAQ)
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Error 108) appears if the stress analysis cannot be performed because the design situation preset for the design has not been defined.
By default, RF‑CONCRETE Surfaces requires a load or a load case from the "characteristic design situation" for the stress analysis of the reinforcing steel. If it has not been defined, the design is not performed and the corresponding error message is displayed.
To avoid this, select a "characteristic load" in the "Serviceability Limit State" tab of Window "1.1 General Data." See the video.
As an alternative, you can change the detailed settings for the serviceability limit state design, so that the stress analysis is performed with a quasi-permanent load, for example. However, this change of the default setting or standard specifications is at the discretion of the user.
First, check if the "design of deformation" has been activated in the settings for the calculation of the SLS designs.
Furthermore, check whether a load for the "quasi-permanent" design situation has been specified in the "Serviceability" tab of Window 1.1. By default, the calculation of deformations in RF‑CONCRETE Surfaces (with RF‑CONCRETE Deflect or RF‑CONCRETE NL) requires a quasi-permanent load.
The "common surfaces" (Column I in Window 1.5) have an informative character.
In theory, you can select or deselect the surfaces to be considered in the punching shear design, and thus shorten the critical perimeter (see the video).
It is usually not necessary to make any changes here.
No, RF-/FOUNDATION Pro does not perform any crack width analysis.
To design a larger foundation plate, where the crack width control may be necessary for the restraint due to the hydration heat formation, you can use RF‑CONCRETE Surfaces. RF-CONCRETE Surfaces allows for the crack width calculation.
No, the function for the shear force reduction that you know from RF‑CONCRETE Members is not available in RF‑CONCRETE Surfaces. RF‑CONCRETE Surfaces always performs the design in the respective FE mesh nodes or grid points.
In the first instance, the determination of the statically required reinforcement (ULS) is independent of the manual specification of the reinforcement areas.
However, if you want to perform the serviceability limit state checks, you have to manually assign the reinforcement to all surfaces selected for design in RF‑CONCRETE Surfaces.
Otherwise, RF‑CONCRETE Surfaces does not apply any reinforcement at the location for the SLS design. The statically required reinforcement is not applied in this case.
In the result windows 3.x, a message is displayed (for the unreinforced surfaces), saying that the reinforcement definition is not sufficient. No check is possible these surfaces.
If you have performed a calculation in RF‑CONCRETE Surfaces, the results are available on FE mesh nodes and on grid points.
If you set a user-defined result value in a surface, an interpolated value from the existing values from the calculation in RF‑CONCRETE Surfaces is displayed on the FE mesh nodes first. This interpolated value is displayed while the user-defined result value is being set (when moving the mouse pointer over the surface).
If closing the command to set the user-defined result value (ESC key), RF‑CONCRETE Surfaces recalculates this actual value at this location. As a consequence, the solver window is displayed briefly. Depending on the complexity of the calculation, this solver window is only displayed for a short time or several seconds.
Due to the initial display of the interpolated values and the subsequent calculation of the actual result value, there may be small differences.
In the case of a calculating in RF‑CONCRETE NL, the creep is applied as a reduction of the elastic modulus of of the concrete in the compression zone of the cross-section.
For more information about the differences between the analytical and nonlinear deformation analysis in RF‑CONCRETE Members and RF‑CONCRETE Surfaces, see the technical articles under the links below.
AnswerFor this, there is an option in the "Combination Expressions" tab when activating the automatic combinations, which allows you to activate the favorably acting permanent loads.
RF-CONCRETE Columns designs a provided reinforcement to perform a stability analysis using the method with nominal curvature.
However, the fire resistance design may require a higher basic reinforcement. For this, you can activate the "User-defined minimum and maximum longitudinal reinforcement" in the "DIN EN 1992‑1‑1" tab of Window 1.4 Reinforcement. Then, you can specify an increased basic reinforcement by clicking the [Edit] button.
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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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