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Frequently Asked Questions (FAQ)
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If the calculation of the longitudinal reinforcement according to the standard is activated, the required reinforcement content is taken into account when displaying the required reinforcement.See the following graphic with the distribution of the required reinforcement without the minimum longitudinal reinforcement according to the standard:Figure 01 - Distribution of Required Reinforcement Without Minimum Longitudinal Reinforcement According to StandardAnd in comparison, the distribution of As,erf,-z(top) with the minimum longitudinal reinforcement according to the standard:Figure 02 - Distribution of Required Reinforcement Incl. Minimum Longitudinal Reinforcement According to StandardIn the result window '2.4 Required Reinforcement by x-Location', you can see which reinforcement is required at each x-location of the designed member. If the minimum longitudinal reinforcement according to the standard becomes relevant, this is indicated by the message No. 26) or 27).At locations where the minimum longitudinal reinforcement is not critical, only the statically required longitudinal reinforcement is displayed. Messages No. 26) and 27) are missing in this case.
AnswerYes, for the nonlinear calculation in RF-CONCRETE Members, it is possible to select the high-strength steel SAS 670 for the design. In this way, you can perform stability analysis for columns, among other things.The steel can be selected in the Materials section of the module (see Figure 01). Since DIN EN 1992-1-1 only allows fyk = 500 N/mm² by default, this limit must be adjusted when using SAS 670.In the general data, you can create a user-defined National Annex where the maximum value of yield strength is increased to fyk ≥ 670 N/mm² in Point 3.2 (see Figure 02).
Please select only members with a reinforced concrete cross-section in the input dialog box 1.6 for the design. If selecting members made of steel (e.g.), you will get the corresponding error message.Figure 01 - Message No. 2379 - Invalid Material DataIn case you select 'All Members', the members with a steel reinforcement area are automatically removed from the design.
AnswerYou will find an option in the "Settings" of the add-on module (see picture 01).
AnswerBoth RFEM and RSTAB are available as solutions. In addition to Eurocode 2, international standards such as ACI 318, CSA A23.3, SIA 262 or GB 50010 are also available for the designing in both programs.
With additional modules for columns, foundations, or punching shear designs, it is possible to calculate the components quickly and reliably.
Main Programs RFEM or RSTABThe main programs RFEM or RSTAB are used to define structures, materials, and Actions.
RFEM is clearly the first choice for solid structures, since in addition to the possibility of creating spatial frame structures, structural systems consisting of plates, walls and shells can be created as well. RFEM is the more diverse variant, as it can be equipped and extended with appropriate additional modules for all materials and designs.
- Eurocode 2 (EN 1992-1-1)
- SIA 262
- ACI 318
- CSA A23.3
- GB 50010
- RF-/CONCRETE Columns
Reinforced concrete design according to the model column method or nominal curvature method
- RF-PUNCH Pro
Punching Shear Designs of Surfaces
- RF-/FOUNDATION Pro
Design of Single, Bucket and Block Foundations
- RF-CONCRETE Deflect (RFEM)
Analytical deformation analysis
- RF-CONCRETE NL
Realistic deformation analysis of surfaces and members
Dynamic AnalysisIf earthquake calculations or vibration analysis of the building are necessary, the RF-/DYNAM Pro Add-on Modules provide suitable tools for determining natural frequencies and shapes, forced vibration analysis, generation of equivalent loads or also for nonlinear time history analysis.If you have any further questions on the Dlubal programs, please do not hesitate to contact the sales department.
AnswerThis may be related to the curtailment of the provided reinforcement.If no curtailment is activated, a uniform reinforcement is designed across the entire structure (Figure 01).
The curtailment of the reinforcement can be activated in the "Longitudinal Reinforcement" tab of the add-on module (Figure 02).
After activating the curtailment, it is possible to define a number of zones. The higher the number of zones is, the more precisely the provided reinforcement can follow the distribution of the required reinforcement (Figure 03).
Yes, it is because the CONCRETE module of RSTAB 8 also includes the nonlinear reinforced concrete design. Thus, you can activate the 'Nonlinear Analysis (State II)' in the 'Ultimate Limit State' tab.
In the detail settings for the nonlinear design, you can select the 'General Design Method for Members in Axial Compression acc. to Second Order Theory'.
It is important that you define the imperfections in RSTAB and apply load curves (CO) according to the second-order analysis for the design, no result combinations (RC)!
Note on RFEM 5:
In RFEM 5, the same procedure is possible in RF-CONCRETE Members. However, the add-on module RF-CONCRETE NL in RFEM is required for the non-linear reinforced concrete design.
AnswerIf any circular cross-sections are available in a structure, they can only be designed with peripheral reinforcement (Figure 01). This is due to the fact that there is no "top" and "bottom" for a circular cross-section.Only one reinforcement layout can be defined for each reinforcement group in RF-CONCRETE Members. If the circular cross-section and the rectangular cross-section are designed together, only the peripheral reinforcement can be used for all cross-sections.To avoid this restriction, you have to define another or separate reinforcement group (Figure 02).
AnswerDifferences resulting from the determination of the deformation in the cracked state can have different causes. The following points should be checked for deviations:
Is the same calculation method applied?
RF-CONCRETE Deflect uses an analytical analysis approach according to EN 1992-1-1 7.4.3.RF-CONCRETE NL uses a physically nonlinear analysis approach.More detailed information about the calculation methods can be found, for example, in the RF-CONCRETE Surfaces Guide in Chapter 2.7 and 2.8.
Is the same initial structure available?
The results of the linear calculation provide the best tool for consideration if the underlying system should be taken for equivalent. The linearly determined deformation of the underlying combination should be approximately equal. Any possible differences in the linear deformation may be increased in the cracked state in connection with the deformation analysis.
Are the same effects taken into account?
When performing a comparison, make sure that the same effects as for example creep and shrinkage are taken into account (Figure 02).
Are the same input values available?
Furthermore, it should be checked in connection with the deformation analysis if the same input values are available. In this case, it is necessary to pay particular attention to whether the applied reinforcement (Figure 03) and the lever arm or concrete cover are the same.
If not having found the cause after the fundamental examination, please contact our hot line.
AnswerThe *.res files do not have a standardized format and it is unfortunately not possible to further process these files externally. This option is mainly used for exchangeability between PC's and the backup.
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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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