In the Modal Analysis add-on, you have the option to automatically increase the sought eigenvalues until reaching a defined effective modal mass factor. All translational directions activated as masses for the modal analysis are taken into account.
Thus, it is possible to easily calculate the required 90% of the effective modal mass for the response spectrum method.
The modal relevance factor (MRF) can help you to assess to which extent specific elements participate in a specific mode shape. The calculation is based on the relative elastic deformation energy of each individual member.
The MRF can be used to distinguish between local and global mode shapes. If multiple individual members show significant MRF (for example, > 20%), the instability of the entire structure or a substructure is very likely. On the other hand, if the sum of all MRFs for an eigenmode is around 100%, a local stability phenomenon (for example, buckling of a single bar) can be expected.
Furthermore, the MRF can be used to determine critical loads and equivalent buckling lengths of certain members (for example, for stability design). Mode shapes for which a specific member has small MRF values (for example, < 20%) can be neglected in this context.
The MRF is displayed by mode shape in the result table under Stability Analysis → Results by Members → Effective Lengths and Critical Loads.
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 "Steel Joints" add-on, you can consider preloaded bolts in all components during the calculation. You can easily activate the preloading using the check box in the bolt parameters, and it has an impact on the stress-strain analysis as well as the stiffness analysis.
Preloaded bolts are special bolts used in steel structures to generate a high clamping force between the connected structural components. This clamping force causes friction between the structural components, which allows for the transfer of forces.
Functionality
Preloaded bolts are tightened with a certain torque, causing them to stretch and generate a tensile force. This tensile force is transferred to the connected components and leads to a high clamping force. The clamping force prevents the connection from loosening and ensures safe force transmission.
Advantages
- High load-bearing capacity: Preloaded bolts can transfer large forces.
- Low deformation: They minimize the deformation of the connection.
- Fatigue strength: They are resistant to fatigue.
- Easy assembly: They are relatively easy to assemble and disassemble.
Analysis and Design
The calculation of preloaded bolts is performed in RFEM using the FE analysis model generated by the "Steel Joints" add-on. It takes into account the clamping force, friction between structural components, shear strength of bolts, and load-bearing capacity of the structural components. The design is carried out according to DIN EN 1993‑1‑8 (Eurocode 3) or the US standard ANSI/AISC 360‑16. You can save the created analysis model, including the results, and use it as an independent RFEM model.
- Consideration of nonlinear component behavior using plastic standard hinges for steel (FEMA 356, EN 1998‑3) and nonlinear material behavior (masonry, steel - bilinear, user-defined working curves)
- Direct import of masses from load cases or combinations for the application of constant vertical loads
- User-defined specifications for the consideration of horizontal loads (standardized to a mode shape or uniformly distributed over the height of the masses)
- Determination of a pushover curve with selectable limit criterion of the calculation (a collapse or limit deformation)
- Transformation of the pushover curve into the capacity spectrum (ADRS format, single degree of freedom system)
- Bilinearization of the capacity spectrum according to EN 1998‑1:2010 + A1:2013
- Transformation of the applied response spectrum into the required spectrum (ADRS format)
- Determination of target displacement according to EC 8 (the N2 method according to Fajfar 2000)
- Graphical comparison of the capacity and required spectrum
- Graphical evaluation of the acceptance criteria of predefined plastic hinges
- Result display of the values used in the iterative calculation of the target displacement
- Access to all results of the structural analysis in the individual load levels
During the calculation, the selected horizontal load is increased in load steps. A static nonlinear analysis is carried out for each load step until reaching the specified limit condition.
The results of the pushover analysis are extensive. On one hand, the structure is analyzed for its deformation behavior. This can be represented by a force-deformation line of the system (a capacity curve). On the other hand, the response spectrum effect can be displayed in the ADRS display (Acceleration-Displacement Response Spectrum). The target displacement is automatically determined in the program based on these two results. The process can be evaluated graphically and in tables.
The individual acceptance criteria can then be graphically evaluated and assessed (for the next load step of the target displacement, but also for all other load steps). The results of the static analysis are also available for the individual load steps.
Have you already discovered the tabular and graphical output of masses in mesh points? That's right, this is also part of the modal analysis results in RFEM 6. This way, you can check the imported masses that depend on various settings of the modal analysis. They can be displayed in the Masses in Mesh Points tab of the Results table. The table provides you with an overview of the following results: Mass - Translational Direction (mX, mY, mZ), Mass - Rotational Direction (mφX, mφY, mφZ), and the Sum of Masses. Would it be best for you to have a graphical evaluation as quickly as possible? Then you can also graphically display the masses in mesh points.
The object types listed below can be graphically assigned to the elements of the structure modeled in the program.
- Nodal supports
- Member shear panels
- Local reductions of member cross-sections
- Member transverse stiffeners
- Member longitudinal welds
- Effective lengths
- Boundary conditions
- Line supports
- Loads
- Member support
- Punching reinforcements
- Mesh refinements
- Surface reinforcements
- Surface results adjustments
- Surface support
- Service classes
- Imperfections
Do you want to consider other loads as masses in addition to the static loads? The program allows that for nodal, member, line and surface loads. For this, you need to select the Mass load type when defining the load of interest. Define a mass or mass components in the X, Y, and Z directions for such loads. For nodal masses, you have an additional option to also specify moments of inertia X, Y, and Z in order to model more complex mass points.
It is often necessary to neglect masses. This is particularly the case when you want to use the output of the modal analysis for the seismic analysis. For this, 90% of the effective modal mass in each direction is required for the calculation. So you can neglect the mass in all fixed nodal and line supports. The program automatically deactivates the associated masses for you.
You can also manually select the objects whose masses are to be neglected for the modal analysis. We have shown the latter in the image for a better view. A user-defined selection is made the and the objects with their associated mass components are selected to neglect the masses.
Is your goal to determine the number of mode shapes? The program offers you two methods for this. On the one hand, you can manually define the number of the smallest mode shapes to be calculated. In this case, the number of available mode shapes depends on the degrees of freedom (that is, the number of free mass points multiplied by the number of directions in which the masses act). However, it is limited to 9999. On the other hand, you can set the maximum natural frequency the way that the program determined the mode shapes automatically until reaching the natural frequency set.
Is the calculation finished? The results of the modal analysis are then available both graphically and in tables. Display the result tables for the load case or the load cases of the modal analysis. Thus, you can see the eigenvalues, angular frequencies, natural frequencies, and natural periods of the structure at first glance. The effective modal masses, modal mass factors, and participation factors are also clearly displayed.
You have several options available to define masses for a modal analysis. While the masses due to self-weight are considered automatically, you can consider the loads and masses directly in a load case of the modal analysis type. Do you need more options? Select whether to consider full loads as masses, load components in the global Z-direction, or only the load components in the direction of gravity.
The program offers you an additional or alternative option for importing masses: A manual definition of load combinations as of which are the masses considered in the modal analysis. Have you selected a design standard? You can then create a design situation with the Seismic Mass combination type. Thus, the program automatically calculates a mass situation for the modal analysis according to the preferred design standard. In other words: The program creates a load combination on the basis of the preset combination coefficients for the selected standard. This contains the masses used for the modal analysis.
Do you want to modify surface stiffnesses? There are now two new types available for you:
- Multiplication factor of total stiffness
- Multiplication factors of partial stiffnesses, weights, and masses
Compared to the RF‑/DYNAM Pro - Natural Vibrations add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Modal Analysis add-on for RFEM 6 / RSTAB 9:
- Preset combination coefficients for various standards (EC 8, ASCE, and so on)
- Optional neglect of masses (for example, mass of foundations)
- Methods for determining the number of mode shapes (user-defined, automatic - to reach effective modal mass factors, automatic - to reach the maximum natural frequency)
- Output of modal masses, effective modal masses, modal mass factors, and participation factors
- Masses in mesh points displayed in tables and graphics
- Various scaling options for mode shapes in the Result navigator
- Automatic consideration of masses from self-weight
- Direct import of masses from load cases or load combinations
- Optional definition of additional masses (nodal, linear, or surface masses, as well as inertia masses) directly in the load cases
- Optional neglect of masses (for example, mass of foundations)
- Combination of masses in different load cases and load combinations
- Preset combination coefficients for various standards (EC 8, SIA 261, ASCE 7,...)
- Optional import of initial states (for example, to consider prestress and imperfection)
- Structure Modification
- Consideration of failed supports or members/surfaces/solids
- Definition of several modal analyses (for example, to analyze different masses or stiffness modifications)
- Selection of mass matrix type (diagonal matrix, consistent matrix, unit matrix), including user-defined specification of translational and rotational degrees of freedom
- Methods for determining the number of mode shapes (user-defined, automatic - to reach effective modal mass factors, automatic - to reach the maximum natural frequency - only available in RSTAB)
- Determination of mode shapes and masses in nodes or FE mesh points
- Results of eigenvalue, angular frequency, natural frequency, and period
- Output of modal masses, effective modal masses, modal mass factors, and participation factors
- Masses in mesh points displayed in tables and graphics
- Visualization and animation of mode shapes
- Various scaling options for mode shapes
- Documentation of numerical and graphical results in printout report
In the modal analysis settings, you have to enter all data that are necessary for the determination of the natural frequencies. These are, for example, mass shapes and eigenvalue solvers.
The Modal Analysis add-on determines the lowest eigenvalues of the structure. Either you adjust the number of eigenvalues or let them determined automatically. Thus, you should reach either effective modal mass factors or maximum natural frequencies. Masses are imported directly from load cases and load combinations. In this case, you have the option to consider the total mass, load components in the global Z-direction, or only the load component in the direction of gravity.
You can manually define additional masses at nodes, lines, members, or surfaces. Furthermore, you can influence the stiffness matrix by importing axial forces or stiffness modifications of a load case or load combination.
- Consideration and display of story masses
- Listing of structural elements and their information
- Automated creation of result sections on shear walls
- Output of section resultants in global direction for determining shear forces
- Optional definition of rigid diaphragm by story (story modeling)
- Stiffness type Floor Slab - Rigid Diaphragm
- Defining floor sets,
- for example, calculation of slabs as a 2D position within the 3D model
- Shear walls: Automatic definition of result members with any cross-section
- Design of rectangular cross-sections using the Concrete Design add-on
- Definition of deep beams
- Design with the Concrete Design add-on
- Tabular output of story actions, interstory drift, and center points of mass and stiffness, as well as the forces in shear walls
- Separate result display of the floor and stiffening design
- Optional neglecting of openings of a certain size
RFEM 6 offers you a wide range of helpful and efficient functions for working with load combinations. You can add the load cases included in load combinations together and then calculate them in consideration of the corresponding factors (partial safety and combination factors, coefficients regarding consequence classes, and so on). Generate the load combinations automatically in compliance with the combination expressions of the standard. You can perform the calculation according to the linear static analysis, second-order analysis, or large deformation analysis, as well as for post-critical analysis. Optionally, you can define whether the internal forces should be related to the deformed or non-deformed structure.
RFEM and RSTAB models can be saved as 3D glTF models (*.glb and *.glTF formats). View the models in 3D in detail with a 3D viewer from Google or Babylon. Take your VR glasses, such as Oculus, to "walk" through the structure.
You can integrate the 3D glTF models into your own websites using JavaScript according to these instructions (as on the Dlubal website Models to Download).
- Design of the following roof types:
- Monopitch roof
- Duopitch Roof
- Curved roof
- All roof shapes allow for a free selection of stiffening diagonals. The following types are available:
- Falling diagonals
- Rising diagonals
- Crossing diagonals with verticals
- Crossing diagonals without verticals
- Crossing diagonals with steel strips (ties)
- Consideration of window rows in the ridge by selecting an inner intermediate part.
- For design according to EC 5 (EN 1995), the following National Annexes are available:
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DIN EN 1995-1-1/NA:2013-08 (Germany)
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NBN EN 1995-1-1/ANB:2012-07 (Belgium)
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DK EN 1995-1-1/NA:2011-12 (Denmark)
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SFS EN 1995-1-1/NA:2007-11 (Finland)
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NF EN 1995-1-1/NA:2010-05 (France)
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UNI EN 1995-1-1/NA:2010-09 (Italy)
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NEN EN 1995-1-1/NB:2007-11 (Netherlands)
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ÖNORM B 1995-1-1:2015-06 (Austria)
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PN EN 1995-1-1/NA:2010-09 (Poland)
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SS EN 1995-1-1 (Sweden)
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STN EN 1995-1-1/NA:2008-12 (Slovakia)
-
SIST EN 1995-1-1/A101:2006-03 (Slovenia)
-
CSN EN 1995-1-1:2007-09 (Czech Republic)
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BS EN 1995-1-1/NA:2009-10 (the United Kingdom)
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- Simple geometry input with illustrative graphics
- Automatic generation of wind loads
- Automatic creation of required combinations for the ultimate and serviceability limit states, as well as fire resistance design
- Free definition of the load cases to be used
- Extensive material library
- Optional extension of material library by further materials
- Extensive library of permanent loads
- Allocation of framework to service classes and specification of service class categories
- Determination of design ratios, support forces, and deformations
- Info icon indicating successful or failed design
- Color reference scales in result tables
- Direct data export to MS Excel
- DXF interface for preparation production documents in CAD
- Program languages: English, German, Czech, Italian, Spanish, French, Portuguese, Polish, Chinese, Dutch, and Russian
- Verifiable printout report, including all required designs. Printout report available in many output languages; for example, English, German, French, Italian, Spanish, Russian, Czech, Polish, Portuguese, Chinese, and Dutch.
- In the ultimate limit state design, the stiffness of the hinge is divided by the partial safety factor and in the serviceability limit state design calculated using the mean stiffnesses. The limit values for the ultimate and the serviceability limit states can be defined separately.
- Design of the following geometrical types:
- Single-span beams with and without cantilevers
- Continuous beams with and without cantilevers
- Hinged girder system (Gerber beams) with and without cantilevers
- Automatic generation of wind and snow loads
- Automatic creation of required combinations for the ultimate and serviceability limit states, as well as fire resistance design
- For design according to EC 5 (EN 1995), the following National Annexes are available:
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DIN EN 1995-1-1/NA:2013-08 (Germany)
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NBN EN 1995-1-1/ANB:2012-07 (Belgium)
-
DK EN 1995-1-1/NA:2011-12 (Denmark)
-
SFS EN 1995-1-1/NA:2007-11 (Finland)
-
NF EN 1995-1-1/NA:2010-05 (France)
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UNI EN 1995-1-1/NA:2010-09 (Italy)
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NEN EN 1995-1-1/NB:2007-11 (Netherlands)
-
ÖNORM B 1995-1-1:2015-06 (Austria)
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PN EN 1995-1-1/NA:2010-09 (Poland)
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SS EN 1995-1-1 (Sweden)
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STN EN 1995-1-1/NA:2008-12 (Slovakia)
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SIST EN 1995-1-1/A101:2006-03 (Slovenia)
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CSN EN 1995-1-1:2007-09 (Czech Republic)
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BS EN 1995-1-1/NA:2009-10 (the United Kingdom)
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- Consideration of optimization options by user specifications according to the respective standard:
- Shear force reduction of single loads near support
- Shear force reduction of load introduction at the cross-section top point
- Moment redistribution in support zone
- Reduction of torsional stress by means of user-defined entry of moment
- Increase of bending stiffnesses for flat-ended or edgewise bending strains
- Simple geometry input with illustrative graphics
- Extensive material library for both standards
- Optional extension of material library by further materials
- Extensive library of permanent loads
- Allocation of framework to service classes and specification of service class categories
- Determination of design ratios, support forces, and deformations
- Info icon indicating successful or failed design
- Color reference scales in result tables
- Direct data export to MS Excel
- Program languages: English, German, Czech, Italian, Spanish, French, Portuguese, Polish, Chinese, Dutch, and Russian
- Verifiable printout report, including all required designs. Printout report available in many output languages; for example, English, German, French, Italian, Spanish, Russian, Czech, Polish, Portuguese, Chinese, and Dutch.
- Direct import of stp files from various CAD programs
- Design of the following column types:
- Hinged column, optionally with elastic restraint of head or footing
- Bracket, optionally with elastic restraint of footing
- Simple geometry input with illustrative graphics
- Extensive material library
- Allocation of framework to service classes and specification of service class categories
- Detailed settings of the fire resistance design
- Specification of limit deformation for the serviceability limit state design
- Determination of design ratios, support forces, and deformations
- For design according to EC 5 (EN 1995), the following National Annexes are available:
-
DIN EN 1995-1-1/NA:2013-08 (Germany)
-
NBN EN 1995-1-1/ANB:2012-07 (Belgium)
-
DK EN 1995-1-1/NA:2011-12 (Denmark)
-
SFS EN 1995-1-1/NA:2007-11 (Finland)
-
NF EN 1995-1-1/NA:2010-05 (France)
-
UNI EN 1995-1-1/NA:2010-09 (Italy)
-
NEN EN 1995-1-1/NB:2007-11 (Netherlands)
-
ÖNORM B 1995-1-1:2015-06 (Austria)
-
PN EN 1995-1-1/NA:2010-09 (Poland)
-
SS EN 1995-1-1 (Sweden)
-
STN EN 1995-1-1/NA:2008-12 (Slovakia)
-
SIST EN 1995-1-1/A101:2006-03 (Slovenia)
-
CSN EN 1995-1-1:2007-09 (Czech Republic)
-
BS EN 1995-1-1/NA:2009-10 (the United Kingdom)
- Automatic generation of wind and snow loads
- Multiple optional reductions according to the selected standard
- Direct data export to MS Excel
- Program languages: English, German, Czech, Italian, Spanish, French, Portuguese, Polish, Chinese, Dutch, and Russian
- Verifiable printout report, including all required designs. Printout report available in many output languages; for example, English, German, French, Italian, Spanish, Russian, Czech, Polish, Portuguese, Chinese, and Dutch.
- Direct import of stp files from various CAD programs
- Import of materials, cross-sections, and internal forces from RFEM/RSTAB
- Steel design of thin‑walled cross‑sections according to EN 1993‑1‑1:2005 and EN 1993‑1‑5:2006
- Automatic classification of cross-sections according to EN 1993-1-1:2005 + AC:2009, Cl. 5.5.2, and EN 1993-1-5:2006, Cl. 4.4 (cross-section class 4), with optional determination of effective widths according to Annex E for stresses under fy
- Integration of parameters for the following National Annexes:
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DIN EN 1993-1-1/NA:2015-08 (Germany)
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ÖNORM B 1993-1-1:2007-02 (Austria)
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NBN EN 1993-1-1/ANB:2010-12 (Belgium)
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BDS EN 1993-1-1/NA:2008 (Bulgaria)
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DS/EN 1993-1-1 DK NA:2015 (Denmark)
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SFS EN 1993-1-1/NA:2005 (Finland)
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NF EN 1993-1-1/NA:2007-05 (France)
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ELOT EN 1993-1-1 (Greece)
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UNI EN 1993-1-1/NA:2008 (Italy)
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LST EN 1993-1-1/NA:2009-04 (Lithuania)
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UNI EN 1993-1-1/NA:2011-02 (Italy)
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MS EN 1993-1-1/NA:2010 (Malaysia)
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NEN EN 1993-1-1/NA:2011-12 (Netherlands)
- NS EN 1993-1-1/NA:2008-02 (Norway)
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PN EN 1993-1-1/NA:2006-06 (Poland)
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NP EN 1993-1-1/NA:2010-03 (Portugal)
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SR EN 1993-1-1/NB:2008-04 (Romania)
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SS EN 1993-1-1/NA:2011-04 (Sweden)
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SS EN 1993-1-1/NA:2010 (Singapore)
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STN EN 1993-1-1/NA:2007-12 (Slovakia)
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SIST EN 1993-1-1/A101:2006-03 (Slovenia)
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UNE EN 1993-1-1/NA:2013-02 (Spain)
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CSN EN 1993-1-1/NA:2007-05 (Czech Republic)
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BS EN 1993-1-1/NA:2008-12 (the United Kingdom)
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CYS EN 1993-1-1/NA:2009-03 (Cyprus)
- In addition to the National Annexes (NA) listed above, you can also define a specific NA, applying user‑defined limit values and parameters.
- Automatic calculation of all required factors for the design value of flexural buckling resistance Nb,Rd
- Automatic determination of the ideal elastic critical moment Mcr for each member or set of members on every x-location according to the Eigenvalue Method or by comparing moment diagrams. You only have to define the lateral intermediate supports.
- Design of tapered members, unsymmetric sections or sets of members according to the General Method as described in EN 1993-1-1, Cl. 6.3.4
- In the case of the General Method according to Cl. 6.3.4, optional application of "European lateral-torsional buckling curve" according to Naumes, Strohmann, Ungermann, Sedlacek (Stahlbau 77 [2008], pp. 748‑761)
- Rotational restraints can be taken into account (trapezoidal sheeting and purlins)
- Optional consideration of shear panels (for example, trapezoidal sheeting and bracing)
- RF-/STEEL Warping Torsion module extension (license required) for stability analysis according to the second-order analysis as stress analysis including consideration of the 7th degree of freedom (warping)
- Module extension RF-/STEEL Plasticity (license required) for plastic analysis of cross‑sections according to Partial Internal Forces Method (PIFM) and Simplex Method for general cross‑sections (in connection with the RF‑/STEEL Warping Torsion module extension, it is possible to perform the plastic design according to the second‑order analysis)
- Module extension RF-/STEEL Cold-Formed Sections (license required) for ultimate and serviceability limit state designs for cold-formed steel members according to the EN 1993-1-3 and EN 1993-1-5 standards
- ULS design: Selection of fundamental or accidental design situations for each load case, load combination, or result combination
- SLS design: Selection of characteristic, frequent, or quasi-permanent design situations for each load case, load combination, or result combination
- Tension analysis with definable net cross-section areas for member start and end
- Weld designs of welded cross-sections
- Optional calculation of warp spring for nodal support on sets of members
- Graphic of design ratios on cross-section and in RFEM/RSTAB model
- Determination of governing internal forces
- Filter options for graphical results in RFEM/RSTAB
- Representation of design ratios and cross‑section classes in the rendered view
- Color scales in result windows
- Automatic cross-section optimization
- Transfer of optimized cross-sections to RFEM/RSTAB
- Parts lists and quantity surveying
- Direct data export to MS Excel
- Verifiable printout report
- Possibility to include the temperature curve in the report
The cross-section resistance design considers all internal force combinations.
If cross-sections are designed according to the PIF method, the internal forces of the cross-section, which are acting in the system of the principal axes related to the centroid or the shear center, are transformed into a local system of coordinates that rests in the web center and is oriented in the web direction.
The individual internal forces are distributed on the top and bottom flanges as well as on the web, and the limit internal forces of the cross‑section parts are determined. Provided that the shear stresses and the flange moments can be absorbed, the axial load-bearing capacity and the ultimate load capacity for bending of the cross‑section are determined by means of the remaining internal forces and compared to the existing force and moment. If the shear stress or the flange resistance is exceeded, the design cannot be performed.
The Simplex Method determines the plastic enlargement factor with the given internal force combination using the SHAPE‑THIN calculation. The reciprocal value of the enlargement factor represents the design ratio of the cross‑section.
Elliptical cross-sections are analyzed for their plastic load‑bearing capacity on the basis of an analytical nonlinear optimization procedure. This method is similar to the Simplex Method. Separate design cases enable flexible analysis of selected members, sets of members, and actions, as well as of individual cross‑sections.
You can adjust design-relevant parameters such as the calculation of all cross‑sections according to the Simplex Method.
The results of the plastic design are displayed in RF‑/STEEL EC3 as usual. The respective result tables include internal forces, cross‑section classes, overall design, and other result data.
RF-/STEEL EC3 automatically imports the cross-sections defined in RFEM/RSTAB. It is possible to design all thin-walled cross-sections. The program automatically selects the most efficient method according to standards.
The ultimate limit state design takes into account several loads and you can select the interaction designs available in the standard.
The classification of designed cross-sections into Classes 1 to 4 is an essential part of the analysis according to Eurocode 3. This way, you can check the limitation of the design and rotational capacity by means of the local buckling of cross-section parts. RF-/STEEL EC3 determines the c/t-ratios of the cross-section parts subjected to compression stress and performs the classification automatically.
For the stability analysis, you can specify for each member or set of members whether flexural buckling occurs in the y- and/or the z-direction. You can also define additional lateral restraints in order to represent the model close to reality. The slenderness ratio and elastic critical load are determined automatically on the basis of the boundary conditions of RF-/STEEL EC3. The elastic critical moment for lateral-torsional buckling required for the lateral-torsional buckling analysis can be determined automatically or specified manually. The load application point of transverse loads, which has an influence on the torsional resistance, can also be taken into account via the setting in the details. In addition, you can take into account rotational restraints (for example trapezoidal sheeting and purlins) and shear panels (for example trapeziodal sheeting and bracing).
In modern construction, where cross-sections are increasingly slender, the serviceability limit state is an important factor in structural analysis. RF-/STEEL EC3 assigns load cases, load combinations, and result combinations to different design situations. The respective limit deformations are preset in the National Annex and can be adjusted, if necessary. In addition, it is possible to define reference lengths and precambers for the design.
- Full integration in RFEM/RSTAB including import of all relevant information and internal forces
- For design according to EN 1995-1-1, the following National Annexes are available:
-
DIN EN 1995-1-1/NA:2013-08 (Germany)
-
ÖNORM B 1995-1-1:2015-06 (Austria)
-
NBN EN 1995-1-1/ANB:2012-07 (Belgium)
-
BDS EN 1995-1-1/NA:2012-02 (Bulgaria)
-
DK EN 1995-1-1/NA:2011-12 (Denmark)
-
SFS EN 1995-1-1/NA:2007-11 (Finland)
-
NF EN 1995-1-1/NA:2010-05 (France)
-
I S. EN 1995-1-1/NA:2010-03 (Ireland)
-
UNI EN 1995-1-1/NA:2010-09 (Italy)
-
LVS EN 1995-1-1/NA:2012-05 (Latvia)
-
LST EN 1995-1-1/NA:2011-10 (Lithuania)
-
LU EN 1995-1-1/NA:2011-09 (Luxembourg)
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NEN EN 1995-1-1/NB:2007-11 (Netherlands)
-
NS EN 1995-1-1/NA:2010-05 (Norway)
-
PN EN 1995-1-1/NA:2010-09 (Poland)
-
NP EN 1995-1-1 (Portugal)
-
SR EN 1995-1-1/NB:2008-03 (Romania)
-
SS EN 1995-1-1 (Sweden)
-
STN EN 1995-1-1/NA:2008-12 (Slovakia)
-
SIST EN 1995-1-1/A101:2006-3 (Slovenia)
-
UNE EN 1995-1-1/AN:2016-04 (Spain)
-
CSN EN 1995-1-1/NA:2007-09 (Czech Republic)
-
BS EN 1995-1-1/NA:2009-10 (the United Kingdom)
-
CYS EN 1995-1-1/NA:2011-02 (Cyprus)
-
- Extensive material library in compliance with the EN, SIA, and DIN standards
- Design of circular, rectangular, and user-defined composite cross-sections (also hybrids)
- Specific classification of a structure in service classes (SECL) and actions in load duration classes (LDC)
- Design of members and sets of members
- Stability analysis according to the Equivalent Member Method or the second-order analysis
- Determination of governing internal forces
- Icon providing information about successful or failed design
- Visualization of the design criterion on RFEM/RSTAB model
- Automatic cross-section optimization
- Parts lists and quantity surveying
- Data export to MS Excel
- Free configuration of charring time and charring rates, as well as free choice of charring sides for fire design
- Fire resistance designs in the selected standard according to:
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EN 1995-1-2
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SIA 265:2012 + SIA 265-C1:2012
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to DIN 4102-22:2004
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- Import of buckling lengths from the RF-STABILITY/RSBUCK add-on module
- Design of tapered members according to the previously defined cut-to-grain angle
- Ridge design and analysis of transversal tension stresses for defined ridges
- Design of curved members and sets of members
The results of warping torsion analysis are displayed in RF-/STEEL AISC and RF-/STEEL EC3 in the usual way. Among other results, the corresponding result windows include the critical warping and torsional values, internal forces, and design summary.
The graphical display of mode shapes (incl. warping) enables a realistic assessment of buckling behavior.
- Automatic consideration of masses from self-weight
- Direct import of masses from load cases or load combinations
- Optional definition of additional masses (nodal, linear, surface masses, as well as inertia masses)
- Combination of masses in different mass cases and mass combinations
- Preset combination coefficients according to EC 8
- Optional import of normal force distributions (in order to consider prestress, for example)
- Stiffness modification (for example, deactivated members or stiffnesses can be imported from RF-/CONCRETE)
- Consideration of failed supports or members
- Definition of several natural vibration cases (for example, to analyze different masses or stiffness modifications)
- Results of eigenvalue, angular frequency, natural frequency, and period
- Determination of mode shapes and masses in nodes or FE mesh points
- Results of modal masses, effective modal masses, and modal mass factors
- Visualization and animation of mode shapes
- Various scaling options for mode shapes
- Documentation of numerical and graphical results in the printout report
- Graphical input of piping systems and piping components
- Illustrative visualization of piping systems and piping components in RFEM graphic window
- Comprehensive libraries for piping cross‑sections and materials
- Comprehensive libraries for flanges, reducers, tees, and expansion joints
- Consideration of piping structure (insulation, lining, tin‑plate)
- Automatic calculation of stress intensification factors and flexibility factors
- Specific piping action categories for load cases
- Optional automatic combinatorics of load cases
- Consideration of material properties (modulus of elasticity, coefficient of thermal expansion) either during operating temperature (default setting) or during reference (assembly) temperature of material
- Consideration of strain and uplift due to pressure (Bourdon effect)
- Interaction between the supporting structure and the piping system