In the Concrete Design add-on for RFEM 6, you can perform the fire design of reinforced concrete slabs and walls according to the simplified table method (EN 1992‑1‑2, Section 5.4.2 and Tables 5.8 and 5.9).
In the Concrete Design add-on, you can perform the simplified fire resistance design according to Sections 5.3.2 and 5.6 of EN 1992‑1‑2 for columns and beams.
The following design checks are available for the simplified fire resistance design:
Columns: Minimum cross-sectional dimensions for rectangular and circular sections according to Table 5.2a as well as Equation 5.7 for calculating time of fire exposure
Beams: Minimum dimensions and center distances according to Tables 5.5 and 5.6
You can determine the internal forces for the fire resistance design according to two methods.
1 Here, the internal forces of the accidental design situation are included directly into the design.
2 The internal forces of the design at normal temperature are reduced by the factor Eta,fi (ηfi), then used in the fire resistance design.
Furthermore, it is possible to modify the axis distance according to Eq. 5.5.
With the Concrete Design add-on, you can perform the fatigue design of members and surfaces according to EN 1992‑1‑1, Chapter 6.8.
For the fatigue design, you can optionally select two methods or design levels in the design configurations:
Design Level 1: Simplified design according to 6.8.6 and 6.8.7(2): The simplified design is performed for frequent action combinations according to EN 1992‑1‑1, Chapter 6.8.6 (2), and EN 1990, Eq. (6.15b) with the traffic loads relevant in the serviceability state. A maximum stress range according to 6.8.6 is designed for the reinforcing steel. The concrete compressive stress is determined by means of the upper and lower allowable stress according to 6.8.7(2).
Design Level 2: Design of damage equivalent stress acc. to 6.8.5 and 6.8.7(1) (simplified fatigue design): The design using damage equivalent stress ranges is performed for the fatigue combination according to EN 1992‑1‑1, Chapter 6.8.3, Eq. (6.69) with the specifically defined cyclic action Qfat.
The Concrete Design add-on allows you to perform the seismic design of reinforced concrete members according to EC 8. This includes, among other things, the following functionalities:
Seismic design configurations
Differentiation of the ductility classes DCL, DCM, DCH
Option to transfer the behavior factor from a dynamic analysis
Check of the limit value for the behavior factor
Capacity design checks of "Strong column - weak beam"
Detailing and particular rules for curvature ductility factor
Detailing and particular rules for local ductility
In the Concrete Design add-on, you can design structural components made of fiber-reinforced concrete according to the guideline DAfStb Steel Fiber-Reinforced Concrete.
You can use this option for the design according to EN 1992‑1‑1. The design according to the DAfStb guideline is carried out once the concrete of the "Fiber Concrete" type has been assigned to the reinforced structural component.
In the "Shear Reinforcement" tab, you can select the option "Cross-ties over free rebars with active selection in graphic". It allows you to arrange additional cross-ties on free rebars of the longitudinal reinforcement.
You can activate or deactivate the position of the cross-ties in the Info Graphic. The cross-ties are applied for the ultimate limit state design and the structural design checks. They are available for the design according to EN 1992‑1‑1.
The design of cold-formed steel members according to the AISI S100-16 / CSA S136-16 is available in RFEM 6. Design can be accessed by selecting “AISC 360” or “CSA S16” as the standard in the Steel Design Add-on. “AISI S100” or “CSA S136” is then automatically selected for the cold-formed design.
RFEM applies the Direct Strength Method (DSM) to calculate the elastic buckling load of the member. The Direct Strength Method offers two types of solutions, numerical (Finite Strip Method) and analytical (Specification). The FSM signature curve and buckling shapes can be viewed under Sections.
Various design parameters of the cross-sections can be adjusted in the serviceability limit state configuration. The applied cross-section condition for the deformation and crack width analysis can be controlled there.
For this, the following settings can be activated:
Crack state calculated from associated load
Crack state determined as an envelope from all SLS design situations
Cracked state of cross-section - independent of load
A wide range of cross-sections, such as rectangular sections, square sections, T‑sections, circular sections, built-up cross-sections, irregular parametric cross-sections, and many others (suitability for design depends on the selected standard)
Design of cross-laminated timber (CLT)
Design of timber-based materials and laminated veneer lumber according to EC 5
Design of tapered and curved members (design method according to the standard)
Adjustment of the essential design factors and standard parameters is possible
Flexibility due to detailed setting options for basis and extent of calculations
Fast and clear results output for an immediate overview of the result distribution after the design
Detailed output of the design results and essential formulas (comprehensible and verifiable result path)
Numerical results clearly arranged in tables and graphical display of the results in the model
Integration of the output into the RFEM/RSTAB printout report
Did you use the eigenvalue solver of the add-on to determine the critical load factor within the stability analysis? If so, you can then display the governing mode shape of the object to be designed as a result. The eigenvalue solver is available here for the lateral-torsional buckling analysis, depending on the design standard used.
If your design is successful, the relaxed part of your work follows. Because the program does many processes for you. For example, the performed design checks are displayed in a table. It shows you all the result details. Due to the clearly presented design formulas, you will be able to understand the results without any problems. There is no "black box" effect here.
The design checks are carried out at all governing locations of the members and displayed graphically as a result diagram. Furthermore, detailed graphics, such as the stress distribution on a cross-section or the governing mode shape, are available for you in the result output.
All input and result data are part of the RFEM/RSTAB printout report. You can select the report contents and extent specifically for the individual design checks.
Deformation analyses of reinforced concrete surfaces without or with cracks (state II) by applying the approximation method (for example, deformation analysis according to ACI 318-19, 24.3.2.5 or EN 1992‑1‑1, Cl. 7.4.3 )
Tension stiffening of concrete applied between cracks
Optional consideration of creep and shrinkage
Graphical representation of results integrated in RFEM, such as deformation or sag of a flat slab
Clear numerical result display in the detail dialog box
Complete integration of results in the RFEM printout report
Are you looking for a deformation calculation? Check the Serviceability Configuration, where it can be activated. You can also control the consideration of long-term effects (creep and shrinkage) and tension stiffening between cracks in the dialog box above. The creep coefficient and shrinkage strain are calculated using the specified input parameters, or you can define them individually.
Furthermore, you can specify the deformation limit value individually for each structural component. The max. deformation is defined as the allowable limit value. In addition, you have to specify whether you want to use the undeformed or the deformed system for the design check.
The standards already specify the approximation methods (for example, deformation calculation according to EN 1992‑1‑1, 7.4.3, or ACI 318‑19, 24.3.2.5) that you need for your deformation calculation. In this case, the so-called effective stiffnesses are calculated in the finite elements in accordance with the existing limit state with / without cracks. You can then use these effective stiffnesses to determine the deformations by means of another FEM calculation.
Consider a reinforced concrete cross-section for the calculation of the effective stiffnesses of the finite elements. Based on the internal forces determined for the serviceability limit state in RFEM, you can classify the reinforced concrete cross-section as "cracked" or "uncracked". Do you consider the effect of the concrete between the cracks? In this case, this is done by means of a distribution coefficient (for example, according to EN 1992‑1‑1, Eq. 7.19, or ACI 318‑19, 24.3.2.5). You can assume the material behavior for the concrete to be linear-elastic in the compression and tension zone until reaching the concrete tensile strength. This procedure is sufficiently precise for the serviceability limit state.
When determining the effective stiffnesses, you can take into accout the creep and shrinkage at the "cross-section level." You don't need to consider the influence of shrinkage and creep in statically indeterminate systems in this approximation method (for example, tensile forces from shrinkage strain in systems restrained on all sides are not determined and have to be considered separately). In summary, the deformation calculation is carried out in two steps:
Calculation of effective stiffnesses of the reinforced concrete cross-section assuming linear-elastic conditions
Calculation of the deformation using the effective stiffnesses with FEM
Have you carried out the design successfully? The results of the deformation analysis are now listed in clearly arranged output tables or detailed dialog boxes with info text. The program shows you all intermediate values in a comprehensible manner. Graphical representation of design ratios and deformation in RFEM allows you for a quick overview of critical areas.
Due to the results output of the design checks with all intermediate results, you can follow the calculation to the smallest detail. The complete integration of results in the RFEM printout report ensures that you obtain verifiable structural design.
Dlubal Software makes many of your work steps easier to support you. Thus, the surfaces, members, member sets, materials, surface thicknesses, and sections defined in RFEM/RSTAB are preset to facilitate the data input. You can use the [Select] function at many places of the program to select the elements graphically. Furthermore, you have an access to the global material and cross-section libraries.
You can group surfaces or members into "Configurations", each with different design parameters. This way, it is possible for you to efficiently calculate design alternatives with different boundary conditions or modified cross-sections, for example. You will be amazed how much faster everything works with RFEM/RSTAB.
Is the design completed? Then you can lean back. The design ratios of the individual design checks (for example, ultimate limit state, serviceability limit state, or compliance with the construction rules) are displayed for you in a table. You can also find the required reinforcement listed in clearly arranged output tables. The program shows you all intermediate values in a comprehensible manner.
You can display the results of members as result diagrams on the respective member. Furthermore, you have the option to document the inserted reinforcement for longitudinal and stirrup reinforcement, including sketches, in accordance with current practice.
Select whether you want to display the results of surfaces as isolines, isosurfaces, or numerical values. In addition to the design check ratios, you can display the longitudinal reinforcement according to required, provided, and not covered reinforcement.
The program does a lot of work for you. The members to be designed are directly imported from RFEM/RSTAB.
You can easily define constructional properties of columns as well as other details for determining the required longitudinal and shear reinforcement. In this case, you can manually define the effective length factor ß or import it from the Structure Stability add-on.
Do you want to perform the bending failure design? To do this, analyze the governing locations of the column for axial forces and moments. For the shear resistance design, you can also consider the locations with extreme values of shear forces. During the calculation, you determine whether a standard design is sufficient or whether the column with the moments has to be designed according to the second-order theory. You can then determine these moments using the previously entered specifications. The calculation is divided into three parts:
Load-independent calculation steps
Iterative determination of governing loading taking into account a varying required reinforcement
Safety determination of all acting internal forces, including the designed reinforcement
After a successful calculation, the results are displayed in clearly arranged tables. Each intermediate value is absolutely traceable, making the design checks transparent.
Import of relevant information and results from RFEM
Integrated, editable material and section library
Sensible and complete presetting of input parameters
Punching design on columns (all section shapes), wall ends, and wall corners
Automatic recognition of the punching node position from an RFEM model
Detection of curves or splines as a boundary of the control perimeter
Automatic consideration of all slab openings defined in the RFEM model
Construction and graphical display of the control perimeter
Optional design with unsmoothed shear stress along the control perimeter that corresponds to the actual shear stress distribution in the FE model
Determination of the load increment factor β via full-plastic shear distribution as constant factors according to EN 1992‑1‑1, Sect. 6.4.3 (3), based on EN 1992‑1‑1, Fig. 6.21N, or by a user‑defined specification
Numerical and graphical display of results (3D, 2D, and in sections)
Punching design of the slab without punching reinforcement
Qualitative determination of the required punching reinforcement
Design and analysis of the longitudinal reinforcement
Complete integration of results in an RFEM printout report
RFEM supports you and save you a lot of work. The materials and surface thicknesses defined in RFEM are already preset in the Concrete Design add-on. Thus, you can directly define the nodes to be designed.
Any openings in the area with risk of punching shear are automatically taken into account in the RFEM model. The add-on recognizes the position of the nodes of punching shear and automatically determines whether it is a node of punching shear in the center of the slab, on the edge of the slab, or in a slab corner. Again, you save your time.
You can individually select the method for determining the load increment factor β.
You have two options in RFEM. On the one hand, you can determine the punching load from a single load (from column/loading/nodal support) and the smoothed or unsmoothed shear force distribution along the control perimeter. On the other hand, you can specify them as user-defined.
Calculate the design ratio of the punching shear resistance without punching reinforcement as a design criterion and the program will deliver you the corresponding result. In the case of exceeding the punching shear resistance without punching reinforcement, the program determines the required punching reinforcement as well as the required longitudinal reinforcement for you.
Is the design completed? Then sit back. Because the punching checks are presented for you clearly and with all result details. This allows you to precisely follow each result. The program shows you the provided and allowable shear stresses for the shear resistance of the slab in detail.
RFEM has even more to offer in this add-on. In the next result window, it lists the required longitudinal or punching reinforcement of each analyzed node. You can also find an explanatory graphic there. RFEM shows you the design results clearly displayed with values in the work window. You can integrate all result tables and graphics into the global printout report of RFEM. Thus, you can be sure of a clear documentation.
Full integration in RFEM/RSTAB with import of geometry and load case data
Automatic selection of members for design according to specified criteria (e.g. only vertical members)
In connection with the extension EC2 for RFEM/RSTAB, you can perform the design of reinforced concrete compression elements according to the method based on nominal curvature in compliance with EN 1992 -1‑1:2004 (Eurocode 2) and the following National Annexes:
DIN EN 1992-1-1/NA/A1:2015-12 (Germany)
ÖNORM B 1992-1-1:2018-01 (Austria)
Belgium NBN EN 1992-1-1 ANB:2010 for design at normal temperature, and NBN EN 1992-1-2 ANB:2010 for fire resistance design (Belgium)
BDS EN 1992-1-1:2005/NA:2011 (Bulgaria)
EN 1992-1-1 DK NA:2013 (Denmark)
NF EN 1992-1-1/NA:2016-03 (France)
SFS EN 1992-1-1/NA:2007-10 (Finland)
UNI EN 1992-1-1/NA:2007-07 (Italy)
LVS EN 1992-1-1:2005/NA:2014 (Latvia)
LST EN 1992-1-1:2005/NA:2011 (Lithuania)
MS EN 1992-1-1:2010 (Malaysia)
NEN-EN 1992-1-1+C2:2011/NB:2016 (Netherlands)
NS EN 1992-1 -1:2004-NA:2008 (Norway)
PN EN 1992-1-1/NA:2010 (Poland)
NP EN 1992-1-1/NA:2010-02 (Portugal)
SR EN 1992-1-1:2004/NA:2008 (Romania)
SS EN 1992-1-1/NA:2008 (Sweden)
SS EN 1992-1-1/NA:2008-06 (Singapore)
STN EN 1992-1-1/NA:2008-06 (Slovakia)
SIST EN 1992-1-1:2005/A101:2006 (Slovenia)
UNE EN 1992-1-1/NA:2013 (Spain)
CSN EN 1992-1-1/NA:2016-05 (Czech Republic)
BS EN 1992-1-1:2004/NA:2005 (United Kingdom)
TKP EN 1992-1-1:2009 (Belarus)
CYS EN 1992-1-1:2004/NA:2009 (Cyprus)
In addition to the National Annexes (NA) listed above, you can define a specific NA, applying user-defined limit values and parameters.
Optional consideration of creep
Diagram-based determination of buckling lengths and slenderness from the restraint ratios of columns
Automatic determination of ordinary and unintentional eccentricity from additionally available eccentricity according to the second-order analysis
Design of monolithic structures and precast elements
Analysis with regard to the standard reinforced concrete design
Determination of internal forces according to the linear static analysis and the second-order analysis
Analysis of governing design locations along the column due to existing loading
Output of required longitudinal and stirrup reinforcement
Fire resistance design according to the simplified method (zone method) according to EN 1992-1-2 allowing the fire resistance design of brackets.
Fire resistance design with optional longitudinal reinforcement design according to DIN 4102-22:2004 or DIN 4102-4:2004, Table 31
Longitudinal and link reinforcement proposal with graphic display in 3D rendering
Summary of design ratios, including all design details
Graphical representation of relevant design details in RFEM/RSTAB work window