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Answer
The increase of the crack factor k_{cr} still has to be done manually because the program does not know where the end of the grain is defined. To do this, divide the member by 1.5 m from the end of the grain so that the affected areas can be designed as a separate member (see Figure 01).Two design cases are now required (File → New Case ...). In case 1, members within the 1.5 m are selected for the design. In case 2, it is necessary to select the members where the 30% needs to be considered. Then, in case 2, the k_{cr} value is adjusted manually in the settings for the National Annex. Thus, a k_{cr} of 0.65 results for C24, which is entered as shown in Figure 02. The design is carried out this way with an increased k_{cr} value. 
Answer
Please deactivate the "indirect calculation" using the limit diameter "lim d_{s}" or the member spacing "lim s_{l}."The calculation of crack widths smaller than 0.20 mm is only possible by using the direct calculation according to EN 1992‑1‑1, 7.3.4. 
Answer
No, this is unfortunately not possible.If the "Tension Stiffening" option is not applied for the calculation, the damage parameter ζ is either "0" for "uncracked sections" or "1" for "cracked sections." For this, see the technical article about the distribution of the damage parameter ζ under Downloads below.Nevertheless, the manual specification of ζ = 0.5, for example, is not possible. 
Answer
The concrete tensile strength f_{ct, eff, wk} = f_{ctm} × crack width factor is applied. 
Answer
The cracking moment of a concrete crosssection is calculated from the mean tensile strength of the concrete and the ideal section modulus. The cracking moment describes the internal force that occurs when the tension stress f_{ctm} is reached in the outermost fiber of the crosssection and crack formation occurs.For uniaxial bending, it is possible to calculate the cracking moment analytically. For biaxial bending, the introduction of a weight factor k is helpful to determine M_{cr} from the components M_{cr,y} and M_{cr,z}.
Calculation for the attached example:Bending moment M_{y} = 20 kNmBending moment M_{z} = 20 kNmIdeal section modulus W_{y} = 3,081 cm^{3}
Ideal section modulus W_{z} = 3,081 cm^{3}^{}Mean tensile strength of concrete f_{ctm} = 0.290 kN/cm²Member 1: Uniaxial bending M_{y}:$\begin{array}{l}M_{cr\;}=f_{ctm}\times W_y\\M_{cr\;}=0.29\;\frac{kN}{cm^2}\times3,081\;cm^3\\M_{cr\;}=893\;kNcm\;=\;8.9\;kNm\end{array}$Member 2: Uniaxial bending M_{z}:$\begin{array}{l}M_{cr\;}=f_{ctm}\times W_z\\M_{cr\;}=0.29\;\frac{kN}{cm^2}\times3,081\;cm^3\\M_{cr\;}=893\;kNcm\;=\;8.9\;kNm\end{array}$Member 3: Biaxial bending M_{y} and M_{z}:$\begin{array}{l}M_{cr\;}=\sqrt{M_{cr,y}^2+M_{cr,z}^2}\\M_{cr,y\;}=k\times My\\k=\frac{f_{ctm}}{\sigma_M}\\\sigma_M=\frac{M_y}{W_y}+\frac{M_z}{W_z}=\\\end{array}$ 
Answer
The crack depth is used to specify the height of the crosssection referring to damage, or, in other words, to a stiffness modification. The nonlinear calculation and the associated layer arrangement of the FE element (see Figure 02) is the basis for the results of this value.
The results of the crack depth are displayed by side and in both principal directions of the cracks. The direction is also able to relate to the trajectories ϕ,hw. 
Answer
You can activate the export of nonlinear stiffness of a cracked structure in Settings for Nonlinear Calculation of the RF‑CONCRETE Members or RF‑CONCRETE Surfaces addon modules. In the Edit Load Cases and Combinations dialog box, select "Extra options" for the selected combinations. A new tab appears where you can activate the transfer of stiffnesses from the addon modules. 
Answer
To apply this in the program, it is necessary to copy the "Temperature" load case (see Figure 01). All loads contained in the load case will be copied as well. One of the load cases is used for the ultimate limit state (ULS) load combinations, the other one for the serviceability limit state (SLS). The loading in the load case for ULS is now multiplied by 1.0/1.5 = 0.667 (see Figure 02).
In order to ensure that both load cases do not occur simultaneously, but only for the specific design situation, the exceptions are determined in the respective combination expressions. For ULS, it is quite simple to define the dead load case in the way that it is not combined with the temperature load case for SLS (see Figure 03). SLS applies exactly the other way around, that is, the load case of dead load is not combined with the temperature for ULS (see Figure 04). In this case, the "Differently for each combination expression" option must be activated.
The desired load combinatorics is then obtained (see Figure 05).

Answer
Message No. 226 appears in the result windows 3.1 to 3.3 in RF‑CONCRETE Surfaces if the concrete tensile stresses from the defined load for the surface to be designed are smaller than the concrete tensile strength.
In this case, the message 226 is displayed with the corresponding information.By clicking the the [i] button, you can open the design details for the respective nondesignable location and display the intermediate values for the determination of the present tensile stress. 
Answer
For the calculation of deformations in cracked sections (state II), the RF‑CONCRETE Deflect extension is available in the RF‑CONCRETE Surfaces addon module.RF‑CONCRETE Deflect requires an explicit load situation for the analytical calculation of deformations in cracked sections (state II), which is only given by using the load combinations (CO). Result combinations do not provide an explicit load situation, no matter if an additive or an enveloped OR combination. Therefore, when applying an RC for the calculation of deformations in RF‑CONCRETE Surfaces by using RF‑CONCRETE Deflect, you receive the mentioned error message. See Figure 01.To avoid this problem, you can simply generate load combinations (CO) instead of result combinations (RC). If you still want to perform the ultimate limit state design with RCs, you can manually create a LC in addition to the existing RCs, for which you want to calculate the deformations by means of RF‑CONCRETE Deflect. See Figure 02.It is important that for the calculation of the deformations, RF‑CONCRETE Surfaces applies the loads from a quasipermanent design situation by default. See Figure 03. This means that the LC, for which the deformations are to be calculated, must be defined as "quasipermanent." As an alternative, it is also possible to userdefine the check boxes for the settings of design situations (see 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 standalone 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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